- Indicates mineral may be doubtful at this locality. - Good crystals or important locality for species. - World class for species or very significant. (TL) - Type Locality for a valid mineral species. (FRL) - First Recorded Locality for everything else (
Bauxite is not a mineral. It is a rock formed from a laterite soil that has been severely leached of silica and other soluble materials in a wet tropical or subtropical climate. It is the primary ore of aluminum. Almost all of the aluminum that has ever been produced has been extracted from bauxite.
"The name montmorillonite is used currently both as a group name for all clay minerals with an expanding lattice, except vermiculite, and also as specific mineral name. Specifically it indicates a high-aluminia end member of the montmorillonite group with some slight replacement of Al3+ by Mg++ and substantially no replacement of Si4+ by Al3+.
Some of the red gems being marketed as red beryl or bixbite are actually pezzottaite, a new gemstone variety that was discovered in Madagascar. Pezzottaite is also very rare - but not yet as valuable as bixbite. It is a different mineral altogether, with a different chemical composition, density and refractive index.
Illite Jade. A dense variety of illite with reddish banding (caused by microscopic inclusions of hematite), which is used for carving and as an ornamental stone. In addition to hematite, the material usually also contains small quantities of impurities such as quartz,...
Brucite may form as a standalone mineral, but it can also form as layers within minerals of the chlorite group and clay minerals such as Montmorillonite and Smectite. It forms a component of certain types of marbles, which are commercially known as pearl grey marble.
Minerals, being natural chemicals, are classified according to their chemistry and crystal form. A basic classification for minerals is: Native elements. eg. Gold, Silver, Mercury, graphite, diamond. Oxides. eg corundum (incl. sapphire), hematite, spinel. Hydroxides. eg. Goethite, brucite. Sulfides. eg. Pyrite, galena, sphalerite. Sulfates. eg.
Oxides. eg corundum (incl. sapphire), hematite, spinel. Hydroxides. eg. Goethite, brucite. Sulfides. eg. Pyrite, galena, sphalerite. Sulfates. eg. Baryte, gypsum. Carbonates. eg. Calcite, magnesite, dolomite. Phosphates. eg. Apatite, monazite. Halides. eg. Fluorite, halite (rock salt). Silicates (most common) Orthosilicates. eg. Garnet, olivine.
Phosphate minerals are those minerals that contain the tetrahedrally coordinated phosphate (PO43−) anion along with the freely substituting arsenate (AsO43−) and vanadate (VO43−). Chlorine (Cl−), fluorine (F−), and hydroxide (OH−) anions that also fit into the crystal structure.
Sphalerite can be found in many ore veins of sulfide minerals, commonly associated with galena and pyrite. Miners call sphalerite "jack," "blackjack," or "zinc blende.". Its impurities of gallium, indium and cadmium make sphalerite a major ore of those metals.