Physics

Moissanite Definition Moissanite is a rare gem that has almost all of the qualities of a diamond. It was first discovered in 1893, with the…

Silicon Carbide Definition Silicon carbide (SiC) is an extremely hard bluish-black insoluble crystalline substance produced by heating carbon with sand at a high temperature and…

Germanium Definition Germanium is a brittle, crystalline, grayish-white metalloid element that is found in coal, in zinc ores, and in several minerals. Its atomic number…

Silicon Definition Silicon is a metalloid element that occurs in both gray crystalline and brown noncrystalline forms. It is the second most abundant element in…

About Brass Definition Brass is a yellowish alloy of copper and zinc, usually 67 percent copper and 33 percent zinc. It sometimes includes small amounts…

Tarnish Definition Tarnish is a substance which forms on the surface of some metals and which stains them or causes them to lose their brightness.…

Thorium Definition Thorium is a silvery-white, radioactive metallic element of the actinide series. The only naturally occurring isotope of thorium, Th 232, is also its…

Titanite Definition Titanite is a very rare calcium titanium silicate that is an important ore of titanium. It is also called Sphene. Its crystals are…

Datolite Definition Datolite is a colourless mineral consisting of a hydrated silicate of calcium and boron in monoclinic crystalline form, occurring in cavities in igneous…

Carbonatite Definition Carbonatite is a carbonate rock of apparent magmatic origin, generally associated with kimberlites and alkalic rocks. It has been variously explained as derived…

Hessonite Definition Hessonite is an orange-brown variety of grossularite garnet also called essonite, cinnamon stone. Its general formula: Ca3Al2Si3O12. It is also known as cinnamon…

Clinohumite Definition Clinohumite is a monoclinic-prismatic mineral containing fluorine, hydrogen, iron, magnesium, oxygen, and silicon. It is an uncommon member of the humite group, a…