mineraloid
21Jet (lignite) — Jet is a geological material and is considered to be a minor gemstone. Jet is not considered a true mineral, but rather a mineraloid as it has an organic origin, being derived from decaying wood under extreme pressure. The English word name jet… …
22Colemanite — For the community in California formerly named Colemanite, see Ryan, California. Colemanite General Category Inoborates …
23Micromount — is term used by mineral collectors and rockhounds to describe mineral specimens that are best appreciated using optical aid, commonly a hand lens or better, a binocular microscope. The magnification employed ranges from 10 to 40 times. A… …
24Moolooite — is a rare blue green mineral with the formula Cu++(C2O4)·n(H2O) (n<1) (making it a hydrated copper oxalate). It was discovered by Richard M Clarke and Ian R Williams in Bunbury Well, Mooloo Downs station, Murchison, Western Australia in… …
25Gummite — from collection of Prague National Museum Gummite is a yellow amorphous mixture of uranium minerals, oxides, silicates and hydrates of uranium, derived from the alteration of uraninite. It is named for its gum like consistence. The material was… …
26Lechatelierite — is silica glass, amorphous SiO2. One common way in which lechatelierite forms naturally is by very high temperature melting of quartz sand during a lightning strike. The result is an irregular, branching, often foamy hollow tube of silica glass… …
27Neelanjali Ruby — The Neelanjali Ruby, at 1,370 carats (274 g), is the world s largest double star ruby. A ruby is known as a star ruby if it contains an asterism (distinctive star shaped light refraction) in the gem. The Neelanjali Ruby is the world s largest… …
28Crookesite — General Category Selenide mineral Chemical formula Cu7(Tl,Ag)Se4 Strunz classification 02.BD.50 …
29Mottramite — General Category Vanadate minerals Chemical formula PbCu(VO4)(OH) Strunz classification 08.BH.40 Crystal symmetry mmm …
30Dogtooth spar — deposited on the walls of a part of the Caverns of Sonora near Sonora, Texas. The former water level can be seen in the upper left hand corner. Dogtooth spar is a speleothem found in limestone caves that consists of very large calcite crystals… …
