The mineral pyrite, or iron pyrite known as fool's gold, is an iron sulfide with the chemical formula FeS2. Pyrite is considered the most common form of sulfide minerals. Pyrite's metallic luster and pale brass-yellow hue give it a superficial resemblance to gold, hence the well-known nickname of fool's gold; the color has led to the nicknames brass and Brazil used to refer to pyrite found in coal. The name pyrite is derived from the Greek πυρίτης, "of fire" or "in fire", in turn from πύρ, "fire". In ancient Roman times, this name was applied to several types of stone that would create sparks when struck against steel. By Georgius Agricola's time, c. 1550, the term had become a generic term for all of the sulfide minerals. Pyrite is found associated with other sulfides or oxides in quartz veins, sedimentary rock, metamorphic rock, as well as in coal beds and as a replacement mineral in fossils, but has been identified in the sclerites of scaly-foot gastropods. Despite being nicknamed fool's gold, pyrite is sometimes found in association with small quantities of gold.

A substantial proportion of the gold is "invisible gold" incorporated into the pyrite. It has been suggested that the presence of both gold and arsenic is a case of coupled substitution but as of 1997 the chemical state of the gold remained controversial. Pyrite enjoyed brief popularity in the 16th and 17th centuries as a source of ignition in early firearms, most notably the wheellock, where a sample of pyrite was placed against a circular file to strike the sparks needed to fire the gun. Pyrite has been used since classical times to manufacture copperas. Iron pyrite was allowed to weather; the acidic runoff from the heap was boiled with iron to produce iron sulfate. In the 15th century, new methods of such leaching began to replace the burning of sulfur as a source of sulfuric acid. By the 19th century, it had become the dominant method. Pyrite remains in commercial use for the production of sulfur dioxide, for use in such applications as the paper industry, in the manufacture of sulfuric acid.

Thermal decomposition of pyrite into FeS and elemental sulfur starts at 540 °C. A newer commercial use for pyrite is as the cathode material in Energizer brand non-rechargeable lithium batteries. Pyrite is a semiconductor material with a band gap of 0.95 eV. Pure pyrite is n-type, in both crystal and thin-film forms due to sulfur vacancies in the pyrite crystal structure acting as n-dopants. During the early years of the 20th century, pyrite was used as a mineral detector in radio receivers, is still used by crystal radio hobbyists; until the vacuum tube matured, the crystal detector was the most sensitive and dependable detector available—with considerable variation between mineral types and individual samples within a particular type of mineral. Pyrite detectors occupied a midway point between galena detectors and the more mechanically complicated perikon mineral pairs. Pyrite detectors can be as sensitive as a modern 1N34A germanium diode detector. Pyrite has been proposed as an abundant, non-toxic, inexpensive material in low-cost photovoltaic solar panels.

Synthetic iron sulfide was used with copper sulfide to create the photovoltaic material. More recent efforts are working toward thin-film solar cells made of pyrite. Pyrite is used to make marcasite jewelry. Marcasite jewelry, made from small faceted pieces of pyrite set in silver, was known since ancient times and was popular in the Victorian era. At the time when the term became common in jewelry making, "marcasite" referred to all iron sulfides including pyrite, not to the orthorhombic FeS2 mineral marcasite, lighter in color and chemically unstable, thus not suitable for jewelry making. Marcasite jewelry does not contain the mineral marcasite; the specimens of pyrite, when it appears as good quality crystals, are used in decoration. They are very popular in mineral collecting. Among the sites that provide the best specimens, highlights the exploited in Navajún, La Rioja. China represents the main importing country with an import of around 376,000 tonnes, which resulted at 45% of total global imports.

China is the fastest growing in terms of the unroasted iron pyrites imports, with a CAGR of +27.8% from 2007 to 2016. In value terms, China constitutes the largest market for imported unroasted iron pyrites worldwide, making up 65% of global imports. From the perspective of classical inorganic chemistry, which assigns formal oxidation states to each atom, pyrite is best described as Fe2+S22−; this formalism recognizes. These persulfide units can be viewed as derived from hydrogen disulfide, H2S2, thus pyrite would be more descriptively, not iron disulfide. In contrast, molybdenite, MoS2, features isolated sulfide centers and the oxidation state of molybdenum is Mo4+; the mineral arsenopyrite has the formula FeAsS. Whereas pyrite has S2 subunits, arsenopyrite has units, formally derived from deprotonation of H2AsSH. Analysis of classical oxidation states would recommend the description of arsenopyrite as Fe3+3−. Iron-pyrite FeS2 represents the prototype compound of the crystallographic pyrite structure.

The structure is simple cubic and was among the first crystal structures solved by X-ray diffraction. It belongs to the crystallographic space group Pa3 and is denoted

Radio Flyer is an American toy company best known for their popular red toy wagon. Radio Flyer produces scooters, bicycles and ride-ons; the company is based in Chicago, Illinois. Antonio Pasin started selling them to area shops, he was working as a craftsman at the time selling phonograph cabinets, built small wooden wagons to carry around his tools. After he received numerous requests from customers of phonograph cabinets to buy the wagons as well, he refocused his business on the wagons, his business grew until the Liberty Coaster Company, named in honour of the Statue of Liberty, was formed in 1923. The demands for these original wooden wagons, dubbed the "Liberty Coaster," outpaced production. Incorporating the mass manufacturing techniques of the auto industry, Pasin began making metal wagons out of stamped steel in 1927. At around that time, the red wagons sold for less than $3, or about $40 in 2016 dollars. In 1930, the company was renamed Radio Manufacturing; the renamed company used assembly line manufacturing techniques.

The new Radio Flyer wagons were named as a tribute to two famous men of the day: Marconi and Lindbergh. Italian inventor and engineer Guglielmo Marconi developed and marketed the first successful long-distance wireless telegraph and in 1901 broadcast the first transatlantic radio signal. Charles Lindbergh completed the first solo, non-stop flight across the Atlantic in 1927. Combining those two marvels, Pasin christened his new metal wagons "Radio Flyer". In 1933, Chicago was the host of the World's Fair, Century of Progress, Radio Steel was asked to be a part of the celebration. Antonio Pasin took on major debt to fund the construction of a 45 foot tall wood and plaster Coaster Boy statue depicting a boy riding a Liberty Coaster wagon. Below the Coaster Boy exhibit Pasin sold miniatures for 25 cents. During World War II, steel was essential war material. In 1987, Radio Steel changed its name to Radio Flyer after its popular flagship little red wagon. Robert Pasin, Antonio's grandson, has been CEO since 1997.

Today, the company produces a wide range of children's products, including scooters, ride-ons, battery ops, wagons. In 2015, Fortune named Radio Flyer number one in the top 25 best small businesses for; the Liberty Coaster Company began producing the wooden bodied "No. 4 Liberty Coaster" in 1923. In 1927, Pasin replaced the wooden body with stamped steel, taking advantage of assembly line manufacturing techniques and earning him the nickname "Little Ford". 1500 wagons a day rolled off assembly lines during the Great Depression. Since 2002, the company has produced plastic as well as metal-bodied wagons. A number of designs and styles have been produced by Radio Flyer inspired by the automobiles or popular culture of the day; the "Zephyr", produced in the 1930s, paid homage to the Chrysler Airflow. The 1950s saw a yellow wagon inspired by the movie Davy Crockett, King of the Wild Frontier and a blue wagon produced in partnership with Disney's Mickey Mouse Club. Wagons from the 1970s borrowed the stylings of the muscle cars of the day, including the Fireball 2001 inspired by Evel Knievel.

The 1990s saw the introduction of the "Quad Shock Wagon" echoing sport utility vehicles. The "Ultimate Family Wagon", introduced in 2007, includes an adjustable seat; the Radio Flyer Wagon was inducted into the National Toy Hall of Fame at The Strong in Rochester, New York in 1999, its creator, Antonio Pasin, was inducted into the Toy Industry Hall of Fame in 2003. The Radio Flyer Tricycle features graphics as the little red wagon; the Inchworm is a wheeled ride-on toy propelled by the bouncing motion of the rider. It is styled as inchworm, it was produced by Hasbro in the 1970s. The Radio Flyer Ziggle, introduced in 2013, is a ride-on toy for kids 3 to 8 with four caster wheels and no pedals. Kids propel forward by wiggling and twisting their bodies in a back and forth motion and moving the handle bars at the same time. In 2016, Radio Flyer introduced the Tesla Model S for Kids; the first and only battery powered ride-on for kids with Lithium Ion Technology. The Flightspeed™ Lithium Ion Batteries are engineered to provide the best performance available with a lower impact on the environment.

It can switch between a top speed of 6 mph and a parent limited speed of 3 mph with the flip of a switch located in the trunk. The car can be personalized; the recognizable little red wagon manufactured by Radio Flyer is used in several artistic works, including film and television. A character in the 1992 drama film Radio Flyer flies to safety in a converted Radio Flyer wagon. Radio Flyer wagons appear in a store display in the 1983 film A Christmas Story; the June 24, 2013 episode of Let's Make a Deal parodied this wagon as a Zonk being offered under the name "Zonk Flyer". The 45 foot tall Coaster Boy wood and plaster statue of a young boy and wagon was constructed by Radio Flyer for the 1933 Chicago World's Fair, Century of Progress. Riverfront Park in Spokane, Washington features a large red wagon that doubles as a playground slide, it is 27 feet long. The interactive sculpture was sculpted by Ken Spiering and installed in 1989; the "World's Largest Wagon" is a sculpture commissioned by Radio Flyer in honor of their 80th anniversary.

It is nine times the size of a little red wagon, weighs 15,000 pounds. Compan

Stanley Noble Rickard was a New Britain-born Australian architect active in Sydney and Los Angeles in the first half of the 20th century. His work in the Federation Bungalow style is listed on the NSW State Heritage Register. Rickard was the first born child of Queensland-born Emma Augusta and New South Wales-born Richard Heath Rickard, his parents had married in Queensland in 1882 and his father was a Wesleyan missionary serving in the Bismarck Archipelago at the time of his birth in New Britain. Rickard's younger siblings were Eda Malila, Albert Sydney and Hazel Alice, his uncle, on his father's side, was Sir Arthur Rickard KBE, married to the daughter of the Sydney architect Thomas Rowe. His first cousin once removed was the architect Bruce Rickard. On the return to Australia of his family, Rickard was educated at state schools in Newcastle and Mudgee. In 1899, he commenced at Newington College under the presidency of the Rev James Egan Moulton where he passed the junior examination. After leaving Newington Rickard worked for four years with Noller and Gawne, builders of Newtown whilst studying architecture at Sydney Technical College.

Upon graduation Rickard was articled to George Sydney Jones ARIBA. In 1904, he went into private practise and soon started work on an estate of thirty first-class residences at Strathfield, a large shop and dwelling at Bondi and a terrace of seven cottages in Ashfield; as early as 1906 he had completed a mansion, known as Lynton, at Burwood. The house is now listed on the New South Wales State Heritage Register, its design is an ornately idiosyncratic version of the architecture of the Federation period. The complexity of the multi-gabled roof line makes the house a landmark in the district, it contains a ballroom, has separate stables and a fernery on its original curtilage. In 1908 he started doing design work for Arnott's Biscuits, he built four brick cottages next to the factory at Homebush and extensive brick stabling and wagon-sheds. Rickard married Ruby Charlotte Chaseling on 2 March 1912 at Redfern. At the wedding reception Rickard presented his new wife with the deeds to a new home in Strathfield.

In September 1923, Ruby Rickard petitioned for divorce on the ground of desertion due to non-compliance to an order for restitution of conjugal rights. He married Ruth McCracken in the USA. Rickard enlisted in Sydney on 1 February 1916 in the Army Service Corps, he embarked from Sydney on 4 May the same year and served for four years in France with the First Australian Imperial Force. After the armistice he studied to become an associate of the Royal Institute of British Architects and returned to Australia via America at his own expense, he disembarked in Sydney on 10 April 1920 and was discharged from the army on 11 June 1920. After his demobilization he practised architecture in Los Angeles. In California Rickard designed homes, flats and theatres and remained for 14 years before returning to Australia in 1935. In 1930 he was the architect and builder of the Dreyer residence at 816 Via Somonte, Malaga Cove, Palos Verdes Estates, California. On his return from America Rickard recommenced his architecture practise in Sydney.

In 1938 he designed Sirocco, at 33 Abingdon Road, Roseville. The house, showing the influence of his time in California, is now heritage listed, he designed the English style cottage next door at number 35. Santa Barbara, at 31 Bannockburn Road Pymble is attributed to Rickard and shows his Californian influence. Rickard was profiled in the publication Notable Citizens of Sydney 1940; the book has a photo and caricature of each person together with a profile, including their vocation, education, recreations and special features. It marks his hobbies as being philately and his recreations as fishing. Rickard is listed as being a member of the Millions Club and the Commercial Travellers Association