February 6, 2019 admin 0

Amethyst is a violet variety of quartz. The name comes from the Koine Greek ἀμέθυστος amethystos from ἀ- a-, “not” and μεθύσκω methysko / μεθύω […]


December 28, 2018 admin 0

Figure 1 – Well-formed garnet crystal Garnets come in a variety of colors and are commonly found in mica-rich metamorphic rocks. (Photo by E. J. […]

Clay Minerals

December 28, 2018 admin 1

Figure 1 – Kaolinite Kaolinite is a common clay mineral formed by weathering of feldspar minerals. Clay is a term used to describe a category […]


December 21, 2018 admin 0

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 […]


December 18, 2018 admin 0

Malachite is a copper carbonate hydroxide mineral, with the formula Cu2CO3(OH)2. This opaque, green banded mineral crystallizes in the monoclinic crystal system, and most often […]


November 29, 2018 admin 0

Gypsum is a soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula CaSO4·2H2O. It is widely mined and is used as a […]


November 23, 2018 admin 0

Apatite is a group of phosphate minerals, usually referring to hydroxylapatite, fluorapatite and chlorapatite, with high concentrations of OH−, F− and Cl− ions, respectively, in […]


November 23, 2018 admin 0

Brazilian trigonal hematite crystal Hematite, also spelled as haematite, is the mineral form of iron(III) oxide (Fe2O3), one of several iron oxides. It is the […]


November 21, 2018 admin 1

Arsenopyrite is an iron arsenic sulfide (FeAsS). It is a hard (Mohs 5.5-6) metallic, opaque, steel grey to silver white mineral with a relatively high […]