Serpentine: A family of silicate minerals rich in magnesium and water, derived from low-temperature alteration or metamorphism of the minerals in ultramafic rocks (intrusive igneous rocks very rich in iron and magnesium and with much less silicon and...
Sterling silver is the standard of quality for articles containing 92.5% silver and 7.5% copper (and/or other alloys).
The fineness of jewelry gold is stated as the number of parts in twenty-four that are gold. Thus, 24 karat gold is pure gold; 12 K would be an alloy that is half gold and half copper or other metals.  
White gold was originally developed to imitate platinum, and is usually an alloy containing 25% nickel and zinc. If stamped 18 karat, it would be 75% pure gold.  
For statistical information about mineral commodities, visit the USGS Commodity Statistics and Information website.  
Mineral elements provide the color in fireworks. Barium produces bright greens; strontium yields deep reds; copper produces blues; and sodium yields yellow. Other colors can be made by mixing elements; strontium and sodium produce brilliant orange;...
The following USGS products will be helpful in determining the background levels of various elements in soils and other surficial materials:Professional Paper 1270. Element Concentrations in Soils and Other Surficial Materials of the Conterminous United...
Fool's Gold can be one of three minerals; the most common mineral mistaken for gold is pyrite, chalcopyrite may also appear gold-like, and weathered biotite mica can mimic flake gold.
An intrusive igneous rock made of plagioclase feldspar and amphibole and/or pyroxene. Similar to gabbro only not as so dark, and containing less iron and magnesium.'Salt and Pepper' Rock:Diorite is of intermediate composition. It is called 'salt and...
A rock is an aggregate of one or more minerals; or a body of undifferentiated mineral matter.