Sand is a granular material composed of finely divided rock and mineral particles. It is defined by size, being finer than coarser than silt. Sand can refer to a textural class of soil or soil type; the composition of sand varies, depending on the local rock sources and conditions, but the most common constituent of sand in inland continental settings and non-tropical coastal settings is silica in the form of quartz. The second most common type of sand is calcium carbonate, for example, created, over the past half billion years, by various forms of life, like coral and shellfish. For example, it is the primary form of sand apparent in areas where reefs have dominated the ecosystem for millions of years like the Caribbean. Sand is a non-renewable resource over human timescales, sand suitable for making concrete is in high demand. Desert sand, although plentiful, is not suitable for concrete, 50 billion tons of beach sand and fossil sand is needed each year for construction; the exact definition of sand varies.
The scientific Unified Soil Classification System used in engineering and geology corresponds to US Standard Sieves, defines sand as particles with a diameter of between 0.074 and 4.75 millimeters. By another definition, in terms of particle size as used by geologists, sand particles range in diameter from 0.0625 mm to 2 mm. An individual particle in this range size is termed a sand grain. Sand grains are between silt; the size specification between sand and gravel has remained constant for more than a century, but particle diameters as small as 0.02 mm were considered sand under the Albert Atterberg standard in use during the early 20th century. The grains of sand in Archimedes Sand Reckoner written around 240 BCE, were 0.02 mm in diameter. A 1953 engineering standard published by the American Association of State Highway and Transportation Officials set the minimum sand size at 0.074 mm. A 1938 specification of the United States Department of Agriculture was 0.05 mm. Sand feels gritty when rubbed between the fingers.
Silt, by comparison, feels like flour). ISO 14688 grades sands as fine and coarse with ranges 0.063 mm to 0.2 mm to 0.63 mm to 2.0 mm. In the United States, sand is divided into five sub-categories based on size: fine sand, fine sand, medium sand, coarse sand, coarse sand; these sizes are based on the Krumbein phi scale, where size in Φ = -log2D. On this scale, for sand the value of Φ varies from −1 to +4, with the divisions between sub-categories at whole numbers; the most common constituent of sand, in inland continental settings and non-tropical coastal settings, is silica in the form of quartz, because of its chemical inertness and considerable hardness, is the most common mineral resistant to weathering. The composition of mineral sand is variable, depending on the local rock sources and conditions; the bright white sands found in tropical and subtropical coastal settings are eroded limestone and may contain coral and shell fragments in addition to other organic or organically derived fragmental material, suggesting sand formation depends on living organisms, too.
The gypsum sand dunes of the White Sands National Monument in New Mexico are famous for their bright, white color. Arkose is a sand or sandstone with considerable feldspar content, derived from weathering and erosion of a granitic rock outcrop; some sands contain magnetite, glauconite or gypsum. Sands rich in magnetite are dark to black in color, as are sands derived from volcanic basalts and obsidian. Chlorite-glauconite bearing sands are green in color, as are sands derived from basaltic lava with a high olivine content. Many sands those found extensively in Southern Europe, have iron impurities within the quartz crystals of the sand, giving a deep yellow color. Sand deposits in some areas contain garnets and other resistant minerals, including some small gemstones. Rocks erode/weather over a long period of time by water and wind, their sediments are transported downstream; these sediments continue to break apart into smaller pieces. The type of rock the sediment originated from and the intensity of the environment gives different compositions of sand.
The most common rock to form sand is Granite, where the Feldspar minerals dissolve faster than the Quartz, causing the rock to break apart into small pieces. In high energy environments rocks break apart much faster than in more calm settings. For example, Granite rocks this means more Feldspar minerals in the sand because it wouldn't have had time to dissolve; the term for sand formed by weathering is epiclastic. Sand from rivers are collected either from the river itself or its flood plain, accounts for the majority of the sand used in the construction industry; because if this, many small rivers have been depleted, causing environmental concern and economic losses to adjacent land. The rate of sand mining in such areas outweighs the rate the sand can replenish, making it a non-renewable resource. Sand dunes are a consequence of wind deposition; the Sahara Desert is dry because of its geographic location and is known for its vast sand dunes. They exist here because little vegetation is able to grow and there's not a lot of water.
Over time, wind blow
Trachyte is an igneous volcanic rock with an aphanitic to porphyritic texture. It is the volcanic equivalent of syenite; the mineral assemblage consists of essential alkali feldspar. Biotite and olivine are common accessory minerals. Chemically, trachyte contains 60 to 65% silica content; these chemical differences are consistent with the position of trachyte in the TAS classification, they account for the feldspar-rich mineralogy of the rock type. Trachytes consist of sanidine feldspar, they have minute irregular steam cavities which make the broken surfaces of specimens of these rocks rough and irregular, from this character they have derived their name. It was first given to certain rocks of this class from Auvergne, was long used in a much wider sense than that defined above; the trachytes are described as being the volcanic equivalents of the plutonic syenites. Their dominant mineral, sanidine feldspar commonly occurs in two generations, i.e. both as large well-shaped porphyritic crystals and in smaller imperfect rods or laths forming a finely crystalline groundmass.
With this there is always a smaller amount of plagioclase oligoclase. Rhomb porphyry is an example with large porphyritic rhomb shaped phenocrysts embedded in a fine-grained matrix. Quartz is rare in trachyte, but tridymite is by no means uncommon, it is in crystals large enough to be visible without the aid of the microscope, but in thin sections it may appear as small hexagonal plates, which overlap and form dense aggregates, like a mosaic or like the tiles on a roof. They cover the surfaces of the larger feldspars or line the steam cavities of the rock, where they may be mingled with amorphous opal or fibrous chalcedony. In the older trachytes, secondary quartz is not rare, sometimes results from the recrystallization of tridymite. Of the mafic minerals present, augite is the most common, it is of pale green color, its small crystals are very perfect in form. Brown hornblende and biotite occur and are surrounded by black corrosion borders composed of magnetite and pyroxene. Olivine is unusual, though found like those of the Arso in Ischia.
Basic varieties of plagioclase, such as labradorite, are known as phenocrysts in some Italian trachytes. Dark brown varieties of augite and rhombic pyroxene are not common. Apatite and magnetite are always present as accessory minerals. Trachytes, being rich in potassium feldspar contain considerable amounts of alkali. Minerals of the feldspathoid group, such as nepheline and leucite, rocks of this kind are known as phonolitic trachytes; the sodium-bearing amphiboles and pyroxenes so characteristic of the phonolites may be found in some trachytes. Trachytic rocks are porphyritic, some of the best known examples, such as the trachyte of Drachenfels on the Rhine, show this character excellently, having large sanidine crystals of tabular form an inch or two in length scattered through their fine-grained groundmass. In many trachytes, the phenocrysts are few and small, the groundmass comparatively coarse; the ferromagnesian minerals occur in large crystals, are not conspicuous in hand specimens of these rocks.
Two types of groundmass are recognized: the trachytic, composed of long, subparallel rods of sanidine, the orthophyric, consisting of small squarish or rectangular prisms of the same mineral. Sometimes granular augite or spongy riebeckite occurs in the groundmass, but as a rule this part of the rock is feldspathic. Glassy forms of trachyte occur, as in Iceland, pumiceous varieties are known, but these rocks as contrasted with the rhyolites have a remarkably strong tendency to crystallize, are to any considerable extent vitreous. Trachytes are well represented among the Cenozoic volcanic rocks of Europe. In Britain they occur in Skye as lava flows and as dikes or intrusions, but they are much more common on the continent of Europe, as in the Rhine district and the Eifel in Auvergne and the Euganean Hills. In the neighborhood of Rome and the island of Ischia trachytic lavas and tuffs are of common occurrence. Trachytes are found on the island of Pantelleria. In the United States, trachytes crop out extensively in the Davis Mountains, Chisos Mountains, Big Bend Ranch State Park in the Big Bend region, as well as southern Nevada and South Dakota.
There is one known voluminous flow from Pu'u Wa'awa'a on the north flank of Hualalai in Hawaii. In Iceland, the Azores, Tenerife an
Petrology is the branch of geology that studies rocks and the conditions under which they form. Petrology has three subdivisions: igneous and sedimentary petrology. Igneous and metamorphic petrology are taught together because they both contain heavy use of chemistry, chemical methods, phase diagrams. Sedimentary petrology is, on the other hand taught together with stratigraphy because it deals with the processes that form sedimentary rock. Lithology was once synonymous with petrography, but in current usage, lithology focuses on macroscopic hand-sample or outcrop-scale description of rocks while petrography is the speciality that deals with microscopic details. In the petroleum industry, lithology, or more mud logging, is the graphic representation of geological formations being drilled through, drawn on a log called a mud log; as the cuttings are circulated out of the borehole they are sampled and tested chemically when needed. Petrology utilizes the fields of mineralogy, optical mineralogy, chemical analysis to describe the composition and texture of rocks.
Petrologists include the principles of geochemistry and geophysics through the study of geochemical trends and cycles and the use of thermodynamic data and experiments in order to better understand the origins of rocks. There are three branches of petrology, corresponding to the three types of rocks: igneous and sedimentary, another dealing with experimental techniques: Igneous petrology focuses on the composition and texture of igneous rocks. Igneous rocks include plutonic rocks. Sedimentary petrology focuses on the texture of sedimentary rocks. Metamorphic petrology focuses on the composition and texture of metamorphic rocks Experimental petrology employs high-pressure, high-temperature apparatus to investigate the geochemistry and phase relations of natural or synthetic materials at elevated pressures and temperatures. Experiments are useful for investigating rocks of the lower crust and upper mantle that survive the journey to the surface in pristine condition, they are one of the prime sources of information about inaccessible rocks such as those in the Earth's lower mantle and in the mantles of the other terrestrial planets and the Moon.
The work of experimental petrologists has laid a foundation on which modern understanding of igneous and metamorphic processes has been built. Important publications in petrology Ore Pedology Atlas of Igneous and metamorphic rocks and textures – Geology Department, University of North Carolina Metamorphic Petrology Database – Department of Earth and Environmental Sciences, Rensselaer Polytechnic Institute Petrological Database of the Ocean Floor - Center for International Earth Science Information Network, Columbia University
The Netherlands is a country located in Northwestern Europe. The European portion of the Netherlands consists of twelve separate provinces that border Germany to the east, Belgium to the south, the North Sea to the northwest, with maritime borders in the North Sea with Belgium and the United Kingdom. Together with three island territories in the Caribbean Sea—Bonaire, Sint Eustatius and Saba— it forms a constituent country of the Kingdom of the Netherlands; the official language is Dutch, but a secondary official language in the province of Friesland is West Frisian. The six largest cities in the Netherlands are Amsterdam, The Hague, Utrecht and Tilburg. Amsterdam is the country's capital, while The Hague holds the seat of the States General and Supreme Court; the Port of Rotterdam is the largest port in Europe, the largest in any country outside Asia. The country is a founding member of the EU, Eurozone, G10, NATO, OECD and WTO, as well as a part of the Schengen Area and the trilateral Benelux Union.
It hosts several intergovernmental organisations and international courts, many of which are centered in The Hague, dubbed'the world's legal capital'. Netherlands means'lower countries' in reference to its low elevation and flat topography, with only about 50% of its land exceeding 1 metre above sea level, nearly 17% falling below sea level. Most of the areas below sea level, known as polders, are the result of land reclamation that began in the 16th century. With a population of 17.30 million people, all living within a total area of 41,500 square kilometres —of which the land area is 33,700 square kilometres —the Netherlands is one of the most densely populated countries in the world. It is the world's second-largest exporter of food and agricultural products, owing to its fertile soil, mild climate, intensive agriculture; the Netherlands was the third country in the world to have representative government, it has been a parliamentary constitutional monarchy with a unitary structure since 1848.
The country has a tradition of pillarisation and a long record of social tolerance, having legalised abortion and human euthanasia, along with maintaining a progressive drug policy. The Netherlands abolished the death penalty in 1870, allowed women's suffrage in 1917, became the world's first country to legalise same-sex marriage in 2001, its mixed-market advanced economy had the thirteenth-highest per capita income globally. The Netherlands ranks among the highest in international indexes of press freedom, economic freedom, human development, quality of life, as well as happiness; the Netherlands' turbulent history and shifts of power resulted in exceptionally many and varying names in different languages. There is diversity within languages; this holds for English, where Dutch is the adjective form and the misnomer Holland a synonym for the country "Netherlands". Dutch comes from Theodiscus and in the past centuries, the hub of Dutch culture is found in its most populous region, home to the capital city of Amsterdam.
Referring to the Netherlands as Holland in the English language is similar to calling the United Kingdom "Britain" by people outside the UK. The term is so pervasive among potential investors and tourists, that the Dutch government's international websites for tourism and trade are "holland.com" and "hollandtradeandinvest.com". The region of Holland consists of North and South Holland, two of the nation's twelve provinces a single province, earlier still, the County of Holland, a remnant of the dissolved Frisian Kingdom. Following the decline of the Duchy of Brabant and the County of Flanders, Holland became the most economically and politically important county in the Low Countries region; the emphasis on Holland during the formation of the Dutch Republic, the Eighty Years' War and the Anglo-Dutch Wars in the 16th, 17th and 18th century, made Holland serve as a pars pro toto for the entire country, now considered either incorrect, informal, or, depending on context, opprobrious. Nonetheless, Holland is used in reference to the Netherlands national football team.
The region called the Low Countries and the Country of the Netherlands. Place names with Neder, Nieder and Nedre and Bas or Inferior are in use in places all over Europe, they are sometimes used in a deictic relation to a higher ground that consecutively is indicated as Upper, Oben, Superior or Haut. In the case of the Low Countries / Netherlands the geographical location of the lower region has been more or less downstream and near the sea; the geographical location of the upper region, changed tremendously over time, depending on the location of the economic and military power governing the Low Countries area. The Romans made a distinction between the Roman provinces of downstream Germania Inferior and upstream Germania Superior; the designation'Low' to refer to the region returns again in the 10th century Duchy of Lower Lorraine, that covered much of the Low Countries. But this time the corresponding Upper region is Upper Lorraine, in nowadays Northern France; the Dukes of Burgundy, who ruled the Low Countries in the 15th century, used the term les pays de par deçà for the Low Countries as opposed to les pays de par delà for their original
Tuff known as volcanic tuff, is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption. Following ejection and deposition, the ash is compacted into a solid rock in a process called consolidation. Tuff is sometimes erroneously called "tufa" when used as construction material, but properly speaking, tufa is a limestone precipitated from groundwater. Rock that contains greater than 50% tuff is considered tuffaceous. Tuff is a soft rock, so it has been used for construction since ancient times. Since it is common in Italy, the Romans used it for construction; the Rapa Nui people used it to make most of the moai statues in Easter Island. Tuff can be classified as either sedimentary or igneous rock, they are studied in the context of igneous petrology, although they are sometimes described using sedimentological terms. The material, expelled in a volcanic eruption can be classified into three types: Volcanic gases, a mixture made of steam, carbon dioxide, a sulfur compound Lava, the name of magma when it emerges and flows over the surface Tephra, chunks of solid material of all shapes and sizes ejected and thrown through the airTephra is made when magma inside the volcano is blown apart by the rapid expansion of hot volcanic gases.
Magma explodes as the gas dissolved in it comes out of solution as the pressure decreases when it flows to the surface. These violent explosions produce solid chunks of material that can fly from the volcano. Chunks smaller than 2 mm in diameter are called volcanic ash. Among the loose beds of ash that cover the slopes of many volcanoes, three classes of materials are represented. In addition to true ashes of the kind described above, lumps of the old lavas and tuffs form the walls of the crater, which have been torn away by the violent outbursts of steam, pieces of sedimentary rocks from the deeper parts of the volcano that were dislodged by the rising lava and are intensely baked and recrystallized by the heat to which they have been subjected. In some great volcanic explosions, nothing but lumps of the old lavas and tuffs forming the walls of the crater etc. were emitted, as at Mount Bandai in Japan in 1888. Many eruptions have occurred in which the quantity of broken sedimentary rocks that mingled with the ash is great.
In the Scottish coalfields, some old volcanoes are plugged with masses consisting of sedimentary debris. These accessory or adventitious materials, however, as distinguished from the true ashes, tend to occur in angular fragments, when they form a large part of the mass, the rock is more properly a "volcanic breccia" than a tuff; the ashes vary in size from large blocks 20 ft or more in diameter to the minutest impalpable dust. The large masses are called "volcanic bombs". Many of them have ribbed or nodular surfaces, sometimes they have a crust intersected by many cracks like the surface of a loaf of bread. Any ash in which they are abundant is called an agglomerate. In those layers and beds of tuff that have been spread out over considerable tracts of land and which are most encountered among the sedimentary rocks, smaller fragments preponderate and bombs more than a few inches in diameter may be absent altogether. A tuff of recent origin is loose and incoherent, but the older tuffs have been, in most cases, cemented together by pressure and the action of infiltrating water, making rocks which, while not hard, are strong enough to be extensively used for building purposes.
If they have accumulated subaerially, like the ash beds found on Mt. Etna or Vesuvius at the present day, tuffs consist wholly of volcanic materials of different degrees of fineness with pieces of wood and vegetable matter, land shells, etc. but many volcanoes stand near the sea, the ashes cast out by them are mingled with the sediments that are gathering at the bottom of the waters. In this way, ashy muds, sands, or in some cases ashy limestones are being formed. Most of the tuffs found in the older formations contain admixtures of clay and sometimes fossil shells, which prove that they were beds spread out under water. During some volcanic eruptions, a layer of ashes several feet in thickness is deposited over a considerable area, but such beds thin out as the distance from the crater increases, ash deposits covering many square miles are very thin; the showers of ashes follow one another after longer or shorter intervals, hence thick masses of tuff, whether of subaerial or of marine origin, have a stratified character.
The coarsest materials or agglomerates show this least distinctly. Apart from adventitious material, such as fragments of the older rocks, pieces of trees, etc. the contents of an ash deposit may be described as consisting of more or less crystalline igneous rocks. If the lava within the crater has been at such a temperature that solidification has commenced, crystals are present, they may be of considerable size like the grey, rounded leucite crystals found on the sides of Vesuvius. Many of these are perfect and rich in faces because they grew in a medium, liquid and not viscous. Good crystals of augite and olivi
The public domain consists of all the creative works to which no exclusive intellectual property rights apply. Those rights may have been forfeited, expressly waived, or may be inapplicable; the works of William Shakespeare and Beethoven, most early silent films, are in the public domain either by virtue of their having been created before copyright existed, or by their copyright term having expired. Some works are not covered by copyright, are therefore in the public domain—among them the formulae of Newtonian physics, cooking recipes, all computer software created prior to 1974. Other works are dedicated by their authors to the public domain; the term public domain is not applied to situations where the creator of a work retains residual rights, in which case use of the work is referred to as "under license" or "with permission". As rights vary by country and jurisdiction, a work may be subject to rights in one country and be in the public domain in another; some rights depend on registrations on a country-by-country basis, the absence of registration in a particular country, if required, gives rise to public-domain status for a work in that country.
The term public domain may be interchangeably used with other imprecise or undefined terms such as the "public sphere" or "commons", including concepts such as the "commons of the mind", the "intellectual commons", the "information commons". Although the term "domain" did not come into use until the mid-18th century, the concept "can be traced back to the ancient Roman Law, as a preset system included in the property right system." The Romans had a large proprietary rights system where they defined "many things that cannot be owned" as res nullius, res communes, res publicae and res universitatis. The term res nullius was defined as things not yet appropriated; the term res communes was defined as "things that could be enjoyed by mankind, such as air and ocean." The term res publicae referred to things that were shared by all citizens, the term res universitatis meant things that were owned by the municipalities of Rome. When looking at it from a historical perspective, one could say the construction of the idea of "public domain" sprouted from the concepts of res communes, res publicae, res universitatis in early Roman law.
When the first early copyright law was first established in Britain with the Statute of Anne in 1710, public domain did not appear. However, similar concepts were developed by French jurists in the 18th century. Instead of "public domain", they used terms such as publici juris or propriété publique to describe works that were not covered by copyright law; the phrase "fall in the public domain" can be traced to mid-19th century France to describe the end of copyright term. The French poet Alfred de Vigny equated the expiration of copyright with a work falling "into the sink hole of public domain" and if the public domain receives any attention from intellectual property lawyers it is still treated as little more than that, left when intellectual property rights, such as copyright and trademarks, expire or are abandoned. In this historical context Paul Torremans describes copyright as a, "little coral reef of private right jutting up from the ocean of the public domain." Copyright law differs by country, the American legal scholar Pamela Samuelson has described the public domain as being "different sizes at different times in different countries".
Definitions of the boundaries of the public domain in relation to copyright, or intellectual property more regard the public domain as a negative space. According to James Boyle this definition underlines common usage of the term public domain and equates the public domain to public property and works in copyright to private property. However, the usage of the term public domain can be more granular, including for example uses of works in copyright permitted by copyright exceptions; such a definition regards work in copyright as private property subject to fair-use rights and limitation on ownership. A conceptual definition comes from Lange, who focused on what the public domain should be: "it should be a place of sanctuary for individual creative expression, a sanctuary conferring affirmative protection against the forces of private appropriation that threatened such expression". Patterson and Lindberg described the public domain not as a "territory", but rather as a concept: "here are certain materials – the air we breathe, rain, life, thoughts, ideas, numbers – not subject to private ownership.
The materials that compose our cultural heritage must be free for all living to use no less than matter necessary for biological survival." The term public domain may be interchangeably used with other imprecise or undefined terms such as the "public sphere" or "commons", including concepts such as the "commons of the mind", the "intellectual commons", the "information commons". A public-domain book is a book with no copyright, a book, created without a license, or a book where its copyrights expired or have been forfeited. In most countries the term of protection of copyright lasts until January first, 70 years after the death of the latest living author; the longest copyright term is in Mexico, which has life plus 100 years for all deaths since July 1928. A notable exception is the United States, where every book and tale published prior to 1924 is in the public domain.
Lime is a calcium-containing inorganic mineral composed of oxides, hydroxide calcium oxide and/ or calcium hydroxide. It is the name for calcium oxide which occurs as a product of coal seam fires and in altered limestone xenoliths in volcanic ejecta; the word lime originates with its earliest use as building mortar and has the sense of sticking or adhering. These materials are still used in large quantities as building and engineering materials, as chemical feedstocks, for sugar refining, among other uses. Lime industries and the use of many of the resulting products date from prehistoric times in both the Old World and the New World. Lime is used extensively for wastewater treatment with ferrous sulfate; the rocks and minerals from which these materials are derived limestone or chalk, are composed of calcium carbonate. They may be crushed, or pulverized and chemically altered. Burning converts them into the caustic material quicklime and, through subsequent addition of water, into the less caustic slaked lime or hydrated lime, the process of, called slaking of lime.
Lime kilns are the kilns used for lime slaking. When the term is encountered in an agricultural context, it refers to agricultural lime, crushed limestone, not a product of a lime kiln. Otherwise it most means slaked lime, as the more dangerous form is described more as quicklime or burnt lime. In the lime industry, limestone is a general term for rocks that contain 80% or more of calcium or magnesium carbonates, including marble, chalk and marl. Further classification is by composition as high calcium, silicious, magnesian and other limestones. Uncommon sources of lime include coral, sea shells and ankerite. Limestone is extracted from mines. Part of the extracted stone, selected according to its chemical composition and optical granulometry, is calcinated at about 1,000 °C in different types of lime kilns to produce quicklime according to the reaction: CaCO 3 calcium carbonate → heat CaO calcium oxide + CO 2 carbon dioxide. Before use, quicklime is hydrated, combined with water, called slaking, so hydrated lime is known as slaked lime, is produced according to the reaction: CaO + H 2 O water ⟶ Ca 2 calcium hydroxide.
Dry slaking is when quicklime is slaked with just enough water to hydrate the quicklime, but remain as a powder and is referred to as hydrated lime. In wet slaking, a slight excess of water is added to hydrate the quicklime to a form referred to as lime putty; because lime has an adhesive property with bricks and stones, it is used as binding material in masonry works. It is used in whitewashing as wall coat to adhere the whitewash onto the wall; the process by which limestone is converted to quicklime by heating to slaked lime by hydration, reverts to calcium carbonate by carbonation is called the lime cycle. The conditions and compounds present during each step of the lime cycle have a strong influence of the end product, thus the complex and varied physical nature of lime products. An example is when slaked lime is mixed into a thick slurry with sand and water to form mortar for building purposes; when the masonry has been laid, the slaked lime in the mortar begins to react with carbon dioxide to form calcium carbonate according to the reaction: Ca2 + CO2 → CaCO3 + H2O.
The carbon dioxide that takes part in this reaction is principally available in the air or dissolved in rainwater so pure lime mortar will not recarbonate under water or inside a thick masonry wall. The lime cycle for dolomitic and magnesium lime is not well understood but more complex because the magnesium compounds slake to periclase which slake more than calcium oxide and when hydrated produce several other compounds thus these limes contain inclusions of portlandite, brucite and other magnesium hydroxycarbonate compounds; these magnesium compounds have limited, contradictory research which questions whether they "...may be reactive with acid rain, which could lead to the formation of magnesium sulfate salts." Magnesium sulfate salts may damage the mortar when they dry and recrystalize due to expansion of the crystals as they form, known as sulfate attack. Lime used in building materials is broadly classified as "pure", "hydraulic", "poor" lime. Uses include lime mortar, lime plaster, lime render, lime-ash floors, tabby concrete, silicate mineral paint, limestone blocks which may be of many types.
The qualities of the many types of processed lime affect. The Romans used two types of lime mortar to make Roman concrete, which allowed them to revolutionize architectur