Sapphire is a precious gemstone, a variety of the mineral corundum, consisting of aluminum oxide with trace amounts of elements such as iron, titanium...
Chalcopyrite is a copper iron sulfide mineral that crystallizes in the tetragonal system. It has the chemical formula CuFeS₂. It has a brassy to gol...
Galena, also called lead glance, is the natural mineral form of lead(II) sulfide. It is the most important ore of lead and an important source of silv...
Feldspar is a group of closely related, rock forming alumino-silicate minerals, which contain varying proportions of potassium, sodium and calcium. Th...