Category
page 1Minerals described in 1969

zemannite
Zemannite is a very rare oxide mineral with the chemical formula Mg0.5ZnFe3+[TeO3]3·4.5H2O. It crystallizes in the hexagonal crystal system and forms small prismatic brown crystals. Because of the rarity and small crystal size, zemannite has no applications and serves as a collector's item.

cuprostibite
Cuprostibite (the name is formed from the addition of two words: cuprum and stibium) — a very rare polymetallic mineral of the sulfide class, consisting of mixed copper and thallium stibnite (although not in all samples), sometimes with admixtures of tin and other metals, ideal formula Cu2(Sb,Tl) or Cu2Sb. The mineral is opaque, it has a metallic luster and a beautiful color from steel gray to violet-pink when freshly chipped.
akdalaite
thumb | right | White vitreous crystal aggregates of the extremely rare Al mineral akdalaite from the TL (Solnechnoye Mine, Kara-Oba, Karazhal, Ulytau Region, Kazakhstan) and only one of 6 known localities worldwide. Ex Vandenbroucke Museum collection from Waregem, Belgium.
Akdalaite (IMA symbol: Akd) is a very rare mineral found in Kazakhstan and has the formula . It was formerly believed to be . It is therefore the same as tohdite an artificially produced phase. Studies on the crystal structure and spectra indicate that this is an aluminium oxide hydroxide.
polarite
Polarite, is an opaque, yellow-white mineral with the chemical formula . Its crystals are orthorhombic pyramidal, but can only be seen through a microscope. It has a metallic luster and leaves a white streak. Polarite is rated 3.5 to 4 on the Mohs Scale.
marthozite
Marthozite is an orthorhombic mineral that has a general formula of Cu(UO2)3(SeO3)3(OH)2·7H2O. It was named after Belgian mineralogist Aimé Marthoz (1894–1962), former Director-general of the Union Minière du Haut Katanga (UMHK).