Titanite, or sphene (from Ancient Greek σφηνώ (sphēnṓ) 'wedge'), is a calcium titanium nesosilicate mineral, CaTiSiO5. Trace impurities of iron and aluminium are typically present. Also commonly present are rare earth metals including cerium and yttrium; calcium may be partly replaced by thorium.
Colemanite (Ca2B6O11·5H2O) or (CaB3O4(OH)3·H2O) is a borate mineral found in evaporite deposits of alkaline lacustrine environments. Colemanite is a secondary mineral that forms by alteration of borax and ulexite.
Spessartine is a nesosilicate, manganese aluminium garnet species, Mn2+3Al2(SiO4)3. This mineral is sometimes mistakenly referred to as spessartite.
Grossular is a calcium-aluminium species of the garnet group of minerals. It has the chemical formula of Ca3Al2(SiO4)3 but the calcium may, in part, be replaced by ferrous iron and the aluminium by ferric iron. The name grossular is derived from the botanical name for the gooseberry, grossularia, in reference to the green garnet of this composition that is found in Siberia. Other shades include cinnamon brown (cinnamon stone variety), red, and yellow. Grossular is a gemstone.
Dumortierite is a fibrous variably colored aluminium boro-silicate mineral, Al7BO3(SiO4)3O3. Dumortierite crystallizes in the orthorhombic system typically forming fibrous aggregates of slender prismatic crystals. The crystals are vitreous and vary in color from brown, blue, and green to more rare violet and pink. Substitution of iron and other tri-valent elements for aluminium result in the color variations. It has a Mohs hardness of 7 and a specific gravity of 3.3 to 3.4. Crystals show pleochroism from red to blue to violet. Dumortierite quartz is blue colored quartz containing abundant dumortierite inclusions.
Hutchinsonite is a sulfosalt mineral of thallium, arsenic and lead with formula (Tl,Pb)2As5S9. Hutchinsonite is a rare hydrothermal mineral.
Kolbeckite (scandium phosphate dihydrate) is a mineral with formula: ScPO4·2H2O. It was discovered originally at Schmiedeberg, Saxony, Germany in 1926 and is named after Friedrich L. W. Kolbeck, a German mineralogist. Kolbeckite is usually found as small clusters of crystals associated with other phosphate minerals.
George Frederick Herbert Smith CBE, known as Herbert Smith, was a British mineralogist who worked for the British Museum. He discovered the mineral paratacamite in 1906, and developed a jeweller's refractometer for the rapid identification of gems. The minerals smithite and herbertsmithite are named after him, as is Herbert's rock-wallaby.
Masuyite is a uranium/lead oxide mineral with formula Pb[(UO2)3O3(OH)2]·3H2O.
Sursassite is a sorosilicate mineral. It was first discovered in 1926. It was first found in the Sursass (Oberhalbstein), a district of Graubünden, Switzerland. It is generally found in deposits of metamorphosed manganese.
Tobermorite is a calcium silicate hydrate mineral with chemical formula: Ca5Si6O16(OH)2·4H2O or Ca5Si6(O,OH)18·5H2O.
Marrite (mar'-ite) is a mineral with the chemical formula PbAgAsS3. It is the arsenic equivalent of freieslebenite (PbAgSbS3), but also displays close polyhedral characteristics with sicherite and diaphorite. Marrite was first described in 1905, and was named in honor of geologist John Edward Marr (1857–1933) of Cambridge, England.
Sinoite is a rare mineral with the chemical formula Si2N2O. It was first found in 1905 in chondrite meteorites and identified as a distinct mineral in 1965. Sinoite crystallizes upon meteorite impact as grains smaller than 0.2 mm surrounded by Fe-Ni alloys and the mineral enstatite. It is named after its SiNO composition and can be prepared in the laboratory as a silicon oxynitride ceramic.
Strashimirite is a rare monoclinic mineral containing arsenic, copper, hydrogen, and oxygen. It has the chemical formula Cu8(AsO4)4(OH)4·5(H2O).
Sarkinite, synonymous with chondrarsenite and polyarsenite, is a mineral with formula Mn2(AsO4)(OH). The mineral is named for the Greek word σάρκιυος, meaning made of flesh, for its red color and greasy luster. The mineral was first noted in Sweden in 1865 as chondrarsenite, though not identified as sarkinite until 1885.
Manganvesuvianite is a rare mineral with formula Ca19Mn3+(Al,Mn3+,Fe3+)10(Mg,Mn2+)2(Si2O7)4(SiO4)10O(OH)9. The mineral is red to nearly black in color. Discovered in South Africa and described in 2002, it was so named for the prevalence of manganese in its composition and its relation to vesuvianite.
Paratacamite is a mineral in the halide minerals category. Its chemical formula is Cu3(Cu,Zn)(OH)6Cl2. Its name is derived from its association with atacamite. Paratacamite was first described by Herbert Smith in 1906. The zincian endmember Cu3(Zn)(OH)6Cl2 is called herbertsmithite, and paratacamite is polymorphous with botallackite and atacamite.
Aspidolite is a mica group phyllosilicate mineral, the sodium analogue of the magnesium-rich mineral phlogopite. The ideal chemical formula for aspidolite is NaMg3AlSi3O10(OH)2.
Sartorite is a lead arsenic sulfide with the chemical formula PbAs2S4 and as type locality the Lengenbach Quarry in Legenbach, Binnental, Valais, Switzerland. Historically, sartorite has been thought isomorphic to chalcostibite, emplectite, and zinckenite, but was definitively distinguished from the others in 1939.
Fumarole minerals are minerals which are deposited by fumarole exhalations. They form when gases and compounds desublimate or precipitate out of condensates, forming mineral deposits. They are mostly associated with volcanoes following deposition from volcanic gas during an eruption or discharge from a volcanic vent or fumarole, but have been encountered on burning coal deposits as well. They can be black or multicoloured and are often unstable upon exposure to the atmosphere.
