The chemical composition of the mineral Linnaeite is indicated by the formula Co3S4, a Cobalt Sulfide. This Linnaeite belongs to the Sulfides mineral class. Linnaeite is considered as an important ore of cobalt and as an ore specimen, it is commonly found exhibiting an interesting image under an ore polarizing light microscope. Linnaeite is also used as mineral specimen and it is often found exhibiting a wonderful appearance when viewed under polarizing microscopes for geologists. Linnaeite is actually uncommon. But still it is considered as an important ore of the strategically valuable metal cobalt.
Mineral Linnaeite was named after C. Linnaeus (1707 ? 1778), a Swedish botanist. The first specimen of Linnaeite was found in 1845 at Vastmanland, Sweden.
Mineral Linnaeite is commonly found having gray to white and especially interesting when viewed under geological polarizing microscopes. It usually tarnishes if exposed to weathering. The luster that is often exhibited by Linnaeite in reflected light of petrographic polarizing light microscope is usually metallic. Mineral Linnaeite is commonly found having imperfect cleavage that is very visible when viewed with the aid of petrographic polarizing light microscopes. It also shows uneven fracture when viewed under polarized light microscopes. The hardness measure of the mineral is often found ranging from 4.5 to 5.5 when the specimen is evaluated using the Mohs scale method. When Linnaeite specimen is rubbed on a white porcelain streak plate, it is often found leaving a black streak. The specific gravity measure of the mineral usually gives an approximate value of about 4.8 grams per cubic centimeters, which is considered average for metallic minerals.
Mineral Linnaeite is commonly known to crystallize in the isometric system, which can be seen clearly visible under a polarizing light microscope for geologists. This isometric system comprises crystals having three axes, all of which are perpendicular to one another and all are found equal in lengths. Most crystals of mineral Linnaeite are found opaque in appearance. The crystal habits of the mineral usually include small octahedral crystals, usually well-formed, and as granular masses in sulfide rocks.
Linnaeite is an isotropic mineral species. This means that it has no power to produce illumination. It also consequently appears dark when viewed between crossed polars of petrographic polarizing microscopes. Mineral Linnaeite forms a red to violet tarnish on weathered specimens. It is commonly found associated with other interesting minerals including covellite, bornite, chalcopyrite, and chalcocite. Linnaeite is a non-magnetic mineral. It is also a non-radioactive mineral species. There is no specific data found on the toxicity and health dangers for mineral Linnaeite. However, the specimens of this mineral species should be treated with great care and use of sensible precaution is advised upon handling them.
The best field indicators of mineral Linnaeite usually include crystal habit, color, tarnish, associations, and streak. Mineral Linnaeite commonly forms with other cobalt sulfides but just a trace. It has formed in large quantities in some few areas including Zaire and Zambia. It can be also found in Maryland and California in USA and also in Seigen, Germany.