Datolite 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 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 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 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…
Jerrygibbsite Jerrygibbsite Definition Jerrygibbsite is a rare silicate mineral with chemical formula: (Mn,Zn)9(SiO4)4(OH)2. It is member of the leucophoenite family of the humite group. It is…
Chondrodite Chondrodite Definition Chondrodite is one of the rarest and most beautiful of gemstones and it is occasionally faceted for collectors. It is a nesosilicate mineral…
Staurolite Staurolite Definition Staurolite is a brownish to black orthorhombic mineral, often having crossed intergrown crystals and found in mica schists and gneisses. Its chemical formula:…
Topaz Topaz Definition Topaz is a colorless, blue, yellow, brown, or pink orthorhombic mineral valued as a gem. Topaz occurs as transparent or translucent prisms in…
Sillimanite Sillimanite Definition Sillimanite is a usually white, pale-green or brown orthorhombic mineral occurring as long, slender, fibrous crystals in metamorphic rocks. It is a polymorph…
Kyanite Kyanite Definition Kyanite is a bluish-green to colorless triclinic mineral. Its chemical formula: Al2SiO5. It occurs as long, thin, blade-shaped crystals in metamorphic rocks. It…
Andalusite Andalusite Definition Andalusite is a hard, grayish white to pinkish brown orthorhombic mineral. It occurs as nearly square prisms, often with cross-shaped cross sections, in…
Thorite Thorite Definition Thorite is a yellow, brownish, or black radioactive mineral consisting of tetragonal thorium silicate. It occurs in coarse granite and is a source…