Search results
Results from the WOW.Com Content Network
Topaz is a silicate mineral made of aluminum and fluorine with the chemical formula Al 2 Si O 4 (F, OH) 2.It is used as a gemstone in jewelry and other adornments. Common topaz in its natural state is colorless, though trace element impurities can make it pale blue or golden brown to yellow-orange. [7]
Michel-Lévy interference colour chart issued by Zeiss Microscopy. In optical mineralogy, an interference colour chart, also known as the Michel-Levy chart, is a tool first developed by Auguste Michel-Lévy to identify minerals in thin section using a petrographic microscope.
A number of individual gemstones are famous in their own right, either because of their size and beauty or because of the people who owned or wore them. Aquamarines [ edit ]
Download as PDF; Printable version; In other projects ... This is a list of gemstones, organized by species ... There are a number of artificial and lab grown ...
The topaz in the Field Museum (2009) The Chalmer's Topaz is a topaz gem weighing 5,899.5- carats located in Chicago, Illinois ' Grainger Hall of Gems, in the Field Museum of Natural History . It was named for former Field Museum trustee William J. Chalmers and his wife Joan Chalmers, who established a fund used to purchase gemstones for the ...
Cardinal gems are gemstones which have traditionally been considered precious above all others. The classification of the cardinal gems dates back to antiquity, and was largely determined by ceremonial or religious use as well as rarity. [1] The term has largely fallen out of use. The five traditional cardinal gems are:
A color chart or color reference card is a flat, physical object that has many different color samples present. They can be available as a single-page chart, or in the form of swatchbooks or color-matching fans. Typically there are two different types of color charts: Color reference charts are intended
Brazilianite, whose name derives from its country of origin, Brazil, is a typically yellow-green phosphate mineral, most commonly found in phosphate-rich pegmatites.. It occurs in the form of perfect crystals grouped in druses, in pegmatites, and is often of precious-stone quality.