KËSTERITE
KËSTERITE Kësterite – Cu2ZnSnS4 – is an extremely rare sulfide. It does not constitute an ore. It is classified within the Stannite Group, in the Kësterite–Stannite series. Its iron (Fe) analogue is ferrokësterite. The synthetic form of kësterite is abbreviated as CZTS (“copper zinc tin sulfide”). The term “kësterite” is sometimes used to encompass both […]
KOBELLITE
KOBELLITE Kobellite – Pb22Cu4(Bi,Sb)30S69 – is a rare sulfosalt typical of high-temperature hydrothermal deposits. It does not constitute the primary ore mineral of the deposit, but occurs within polymetallic ores. It is classified within the Kobellite homologous series group. It is the bismuth analogue of tintinaite, with which it forms a series. It may contain […]
KORNERUPINE
KORNERUPINE Kornerupine – Mg3Al6(Si,Al,B)5O21(OH) – is an extremely rare sorosilicate that is sometimes used as a gemstone, particularly when it occurs in a transparent green form. It is also referred to as “prismatine”—an incorrect designation, as prismatine is a distinct mineral with which kornerupine forms a solid solution. A very rare variety known as “star […]
KRÖHNKITE
KRÖHNKITE Kröhnkite – Na2Cu(SO4)2·2H2O – is a fairly rare sulfate, typically occurring as a secondary copper mineral. Due to its rarity, it is not an important ore. It is classified in the Roselite Group and has an anhydrous phase, saranchinaite, which can be formed by heating kröhnkite to 200ºC. It is readily soluble in water. […]
KERNITE
KERNITE Kernite – Na2[B4O6(OH)2].3H2O – is an extremely rare hydrated borate, important as an ore for the manufacture of “chemical borax,” even more important than borax itself, because kernite contains less water than borax. The deposit in the Kramer District (Boron, California, USA) was for many years the only known occurrence of kernite and the […]
KLAPROTHITE
KLAPROTHITE The designation “klaprothite” has been changed several times: 1) In 1824 the term “klaprothite” was coined by F.S. Beudant, who replaced it in 1832 with “klaprothine”, but the mineral thus designated was actually lazulite and therefore the name was abandoned. 2) In 1868 “klaprothite” was used again, this time by Thomas Petersen to designate […]
KYANITE
KYANITE Kyanite – Al2SiO5 – is a common nesosilicate, typical of metamorphic rocks, constituting an important industrial mineral used in the production of refractories and ceramics. An ancient name for kyanite, still widely used by some authors, is “Disthen”. In Portuguese, the name of the mineral is “Cianita”. Kyanite is one of the three polymorphs […]
KERMESITE
KERMESITE Kermesite – Sb2S2O – also known as “red antimony”, is a relatively common oxide. It is not of great importance as an ore, only being part of polymetallic ores containing Sb. Kermesite crusts and coatings can be confused with metastibnite. 1. Characteristics Crystal system: Triclinic pinacoidal, pseudomonoclinic. Color: Crimson red or dark red, it […]
KOSMOCHLOR
KOSMOCHLOR Kosmochlor – NaCr(Si2O6) – is a very rare inosilicate, from the Clinopyroxene Subgroup (Pyroxene Group). It is important as an ore because it is a constituent of the ornamental rock “Maw Sit Sit”. It may contain, as impurities, Mn, Mg, Fe, Ti, Ca, K, P and Al. 1. Characteristics Crystal system: Monoclinic prismatic. […]
KAMACITE
KAMACITE Kamacite – (Fe,Ni) – is a Ni-rich variety of native iron. It is abundant in Fe-Ni meteorites (siderites) and also occurs in most other types of meteorites, with the exception of some rocky meteorites. It does not occur in terrestrial geological situations and will not be discussed here in detail. May contain Co, C, […]