A mineral is, broadly speaking, a solid chemical compound that occurs in pure form. Minerals are most associated with rocks due to the presence of minerals within rocks; these rocks may consist of one type of mineral, or may be an aggregate of two or more different types of minerals, spacially segregated into distinct phases. Compounds that occur only in living beings are excluded, but some minerals are biogenic or are organic compounds in the sense of chemistry. Moreover, living beings synthesize inorganic minerals that occur in rocks. In geology and mineralogy, the term "mineral" is reserved for mineral species: crystalline compounds with a well-defined chemical composition and a specific crystal structure; some natural solid substances without a definite crystalline structure, such as opal or obsidian, are more properly called mineraloids. If a chemical compound may occur with different crystal structures, each structure is considered different mineral species. Thus, for example and stishovite are two different minerals consisting of the same compound, silicon dioxide.

The International Mineralogical Association is the world's premier standard body for the definition and nomenclature of mineral species. As of March 2020, the IMA recognizes 5,562 official mineral species out of more than 5,750 proposed or traditional ones; the chemical composition of a named mineral species may vary somewhat by the inclusion of small amounts of impurities. Specific varieties of a species sometimes have official names of their own. For example, amethyst is a purple variety of the mineral species quartz; some mineral species can have variable proportions of two or more chemical elements that occupy equivalent positions in the mineral's structure. Sometimes a mineral with variable composition is split into separate species, more or less arbitrarily, forming a mineral group. Besides the essential chemical composition and crystal structure, the description of a mineral species includes its common physical properties such as habit, lustre, colour, tenacity, fracture, specific gravity, fluorescence, radioactivity, as well as its taste or smell and its reaction to acid.

Minerals are classified by key chemical constituents. Silicate minerals comprise 90% of the Earth's crust. Other important mineral groups include the native elements, oxides, carbonates and phosphates. One definition of a mineral encompasses the following criteria: Formed by a natural process. Stable or metastable at room temperature. In the simplest sense, this means. Classical examples of exceptions to this rule include native mercury, which crystallizes at −39 °C, water ice, solid only below 0 °C. Modern advances have included extensive study of liquid crystals, which extensively involve mineralogy. Represented by a chemical formula. Minerals are chemical compounds, as such they can be described by fixed or a variable formula. Many mineral groups and species are composed of a solid solution. For example, the olivine group is described by the variable formula 2SiO4, a solid solution of two end-member species, magnesium-rich forsterite and iron-rich fayalite, which are described by a fixed chemical formula.

Mineral species themselves could have a variable composition, such as the sulfide mackinawite, 9S8, a ferrous sulfide, but has a significant nickel impurity, reflected in its formula. Ordered atomic arrangement; this means crystalline. An ordered atomic arrangement gives rise to a variety of macroscopic physical properties, such as crystal form and cleavage. There have been several recent proposals to classify amorphous substances as minerals; the formal definition of a mineral approved by the IMA in 1995: "A mineral is an element or chemical compound, crystalline and, formed as a result of geological processes." Abiogenic. Biogenic substances are explicitly excluded by the IMA: "Biogenic substances are chemical compounds produced by biological processes without a geological component and are not regarded as minerals. However, if geological processes were involved in the genesis of the compound the product can be accepted as a mineral."The first three general characteristics are less debated than the last two.

Mineral classification schemes and their definitions are evolving to match recent advances in mineral science. Recent changes have included the addition of an organic class, in both the new Dana and the Strunz classification schemes; the organic class includes a rare group of minerals with hydrocarbons. The IMA Commission on New Minerals and Mineral Names adopted in 2009 a hierarchical scheme for the naming and classification of mineral groups and group names and established seven commissions and four

George Blumenthal (banker)

George Blumenthal was a German-born banker who served as the head of the U. S branch of Lazard Frères. Blumenthal was born in Frankfurt am Main in 1858. Blumenthal a foreign-exchange banker was sent to the United States by Speyer & Co. and rose to prominence as the head of the U. S branch of Lazard Frères, he was a partner of Lazard Frères in France. He retired from Lazard in 1901, giving up his seat on the stock exchange, returned as a partner in 1906, he returned to the stock exchange in 1916, purchasing a seat for $63,000. With J. P. Morgan the elder, he was one of five bankers who saved Grover Cleveland from giving up specie payments in 1896, with their $65,000,000 gold loans. In New York, he served as president of the Mount Sinai Hospital, where he donated $2 million and where the Blumenthal auditorium is named after him, he was a trustee of the Metropolitan Museum of Art for many years as well as president of the American Hospital of Paris. He served as the seventh president of the Metropolitan Museum of Art from 1934 until his death in 1941, where he gave $1 million and to which he bequeathed the Patio from the Castle of Vélez Blanco, a colonnaded Spanish Renaissance patio.

After his death, he was succeeded by William Church Osborn. His niece, Katharine Graham, in her memoir Personal History, described her uncle as a "difficult man with a big ego." He and Florence named the Blumenthal Rare Book and Manuscript Library, which contains rare and illustrated books, Haggadot, as a resource for scholarly research. In 1898, Blumenthal was married to Florence Meyer, a daughter of Marc Eugene Meyer and sister of Eugene Isaac Meyer. Together, they were the parents of one son, who died young, George Blumenthal Jr.. After the death of his first wife Florence in 1930, the 77 year old George married Marion "Mary" Clews in December 1935. Mary, a descendant of Sir Robert Payne, was the second wife, widow, of banker James Blanchard Clews, a nephew of Henry Clews. Blumenthal died at his home in New York City on June 26, 1941, his estate was valued in excess of $8,000,000. After his death, his widow remarried to Brig. Gen. Ralph Kenyon Robertson in 1943. After his death, she married Baron Carl von Wrangell-Rokassowsky in 1969, becoming the Countess von Wrangell.

George and his second wife endowed the George and Marion Blumenthal Research Scholarships awarded annually for demonstrated merit in community arts leadership by the Roski School of Fine Arts at the University of Southern California. George Blumenthal at Find a Grave The George and Florence Blumenthal home at 50 East Seventieth Street in New York, 1920s, a digitized picture album from The Metropolitan Museum of Art Libraries

Embassy of the United States, Vienna

The Embassy of the United States of America in Vienna is the main United States diplomatic mission to Austria. Since 1947 the embassy building is located on Boltzmanngasse 16, in the Alsergrund district of Vienna; the United States first established diplomatic relations with Austria when Henry A. P. Muhlenberg was appointed first U. S. Envoy Extraordinary and Minister Plenipotentiary to the Austrian Empire on 8 February 1838; when according to the Compromise of 1867 the empire became the union of Austria-Hungary, the Ministers were so commissioned. The legation was elevated to the status of an embassy on 17 May 1902, with Robert Sanderson McCormick as first U. S. Ambassador; when upon the American entry into World War I the United States broke off diplomatic relations with Austria-Hungary in April 1917, Spain handled the representation of U. S. interests in Vienna for the duration of the war. In 1921 the U. S. diplomatic mission reopened as a legation. The Neo-baroque embassy building at Boltzmanngasse 16 was constructed from 1902 to 1904 according to plans designed by architect Ludwig Baumann as the new location of the K.k.

Academy for Oriental Languages established in 1754. The studying conditions were restricted after the Austrian Anschluss to Nazi Germany and the building was temporarily used as a Wehrmacht military hospital. At the conclusion of World War II, U. S. occupation troops seized the building until 1946. The U. S. Government purchased the building on 30 June 1947, at the intercession of Eleanor Lansing Dulles and with the consent of the Austrian National Council; the U. S. Mission in Austria held the status of a legation from 1947 until 1951, when it became an embassy, with Walter J. Donnelly as the first U. S. ambassador to serve in Vienna since Frederic Courtland Penfield departed in World War I. The current United States Ambassador to Austria is Trevor Traina, who presented his credentials to the Austrian president Alexander Van der Bellen on 24 May 2018. Embassy of Austria, Washington, D. C. Embassy of the United States in Vienna