Euxenite, or euxenite-(Y), is a brownish black mineral with a metallic luster.
Zoisite, first known as saualpite, after its type locality, is a calcium aluminum hydroxy sorosilicate belonging to the epidote group of minerals. Its chemical formula is Ca2Al3(SiO4)(Si2O7)O(OH).
Astrophyllite is a very rare, brown to golden-yellow hydrous potassium iron titanium silicate mineral. Belonging to the astrophyllite group, astrophyllite may be classed either as an inosilicate, phyllosilicate, or an intermediate between the two. It forms an isomorphous series with kupletskite, to which it is visually identical and often intimately associated. Astrophyllite is of interest primarily to scientists and collectors.
Proustite is a sulfosalt mineral consisting of silver sulfarsenide, Ag3AsS3, known also as ruby blende, light red silver, arsenic-silver blende or ruby silver ore, and an important source of the metal. It is closely allied to the corresponding sulfantimonide, pyrargyrite, from which it was distinguished by the chemical analyses of Joseph L. Proust (1754–1826) in 1804, after whom the mineral received its name.
Aurichalcite is a carbonate mineral, usually found as a secondary mineral in copper and zinc deposits. Its chemical formula is (Zn,Cu)5(CO3)2(OH)6. The zinc to copper ratio is about 5:4. Copper (Cu2+) gives aurichalcite its green-blue colors.
Adamite is a zinc arsenate hydroxide mineral, Zn2AsO4OH. It is a mineral that typically occurs in the oxidized or weathered zone above zinc ore occurrences. Pure adamite is colorless, but usually it possess yellow color due to Fe compounds admixture. Tints of green also occur and are connected with copper substitutions in the mineral structure. Olivenite is a copper arsenate that is isostructural with adamite and there is considerable substitution between zinc and copper resulting in an intermediate called cuproadamite. Zincolivenite is a recently discovered mineral being an intermediate mineral with formula CuZn(AsO4)(OH). Manganese, cobalt, and nickel also substitute in the structure. An analogous zinc phosphate, tarbuttite, is known.
Esperite is a rare complex calcium lead zinc silicate (PbCa3Zn4(SiO4)4) related to beryllonite and trimerite that used to be called calcium larsenite. It was named in honor of Esper F. Larsen Jr. (1879–1961), petrologist of Harvard University.
Arfvedsonite or soda hornblende (partiellement obsolète) is a sodium amphibole mineral with composition: [Na][Na2][(Fe2+)4Fe3+][(OH)2|Si8O22]. It crystallizes in the monoclinic prismatic crystal system and typically occurs as greenish black to bluish grey fibrous to radiating or stellate prisms.
Xonotlite, or eakleite, is a mineral of general formula Ca6Si6O17(OH)2 named by the German mineralogist Karl Friedrich August Rammelsberg in 1866. The name originates from its discovery locality, Tetela de Xonotla, Puebla, Mexico. Although it was discovered in 1866, it was first described in 1959. It is approved by the IMA, but it is a grandfathered species, meaning the name supposedly represents a valid species til this day.
Clinohedrite is a rare silicate mineral. Its chemical composition is a hydrous calcium-zinc silicate; CaZn(SiO4)·H2O. It crystallizes in the monoclinic system and typically occurs as veinlets and fracture coatings. It is commonly colorless, white to pale amethyst in color. It has perfect cleavage and the crystalline habit has a brilliant luster. It has a Mohs hardness of 5.5 and a specific gravity of 3.28–3.33.
Titanowodginite is a mineral with the chemical formula MnTiTa2O8. Titanowodginite has a Mohs hardness of 5.5 and a vitreous luster. It is an iridescent dark brown to black crystal that commonly forms in a matrix of smoky quartz or white beryl in a complex zoned pegmatite.
Temagamite is a bright white palladium mercury telluride mineral with a hardness of 2+1⁄2 on the Mohs scale. Its chemical formula is Pd3HgTe3. It was discovered at the Temagami Mine on Temagami Island, Lake Temagami in 1973, and it represents a rare mineral in the Temagami Greenstone Belt.
Brownleeite is a silicide mineral with chemical formula MnSi. It was discovered by researchers of the Johnson Space Center in Houston while analyzing the Pi Puppid particle shower of the comet 26P/Grigg-Skjellerup. The only other known natural manganese silicide is mavlyanovite, Mn5Si3.
Népouite is a rare nickel silicate mineral which has the apple green color typical of such compounds. It was named by the French mining engineer Edouard Glasser in 1907 after the place where it was first described, the Népoui Mine, Népoui, Poya Commune, North Province, New Caledonia. The ideal formula is Ni3(Si2O5)(OH)4, but most specimens contain some magnesium, and (Ni,Mg)3(Si2O5)(OH)4 is more realistic. There is a similar mineral called lizardite in which all of the nickel is replaced by magnesium, formula Mg3(Si2O5)(OH)4. These two minerals form a series; intermediate compositions are possible, with varying proportions of nickel to magnesium.
Stillwellite-(Ce) is a rare-earth boro-silicate mineral with chemical formula (Ce,La,Ca)BSiO5.
Abramovite is a very rare mineral from the sulfides and sulfosalt categories. It has the chemical formula Pb2SnInBiS7. It occurs as tiny elongated lamellar-shaped crystals, up 1 mm × 0.2 mm in size, and is characterized by its non-commensurate structure.
Metarauchite is a member of the autunite group, found at the Jáchymov ore district, Czech Republic and in Schneeberg, Germany. The autunite group is a group of structured uranyl phosphates and arsenates; the other members of the group are autunite, bassetite, heinrichite, kahlerite, nováčekite-I, nováčekite-II, rauchite, sabugalite, saléeite, torbernite, uranocircite, uranospinite, and zeunerite. The mineral is named after Czech mineral collector Luděk Rauch, who died in the Jáchymov mines during mineral prospecting.
Minrecordite, CaZn(CO3)2, is a very rare mineral belonging to the dolomite group, the member with Ca and Zn. It was discovered, associated with dioptase, in a specimen from the Tsumeb mine (Namibia), which is consequently its type locality. Its name is a tribute to The Mineralogical Record magazine, representing the collaboration between professional and amateur mineralogists. In this locality it is associated primarily with dioptase, and less frequently with duftite, calcite and malachite. It is a rare mineral, which has been found only in a few deposits in the world. In addition to the type locality, it appears in the Preguiça mine, in Moura, district of Beja (Portugal).
Baratovite is a very rare cyclosilicate mineral named after Rauf Baratovich Baratov from Tajikistan. It was discovered in 1974 at Dara-Pioz glacier, Tajikistan, and was approved by the International Mineralogical Association only a year later in 1975. The glacier gives home to 133 valid species, and is the type locality of 33 minerals, one of which is baratovite.
Dresserite is a mineral of the dresserite group, named in honor of John Alexander Dresser, geologist. It was approved by the IMA in 1968, but only a year after was it published. The rare mineral can only be found in Francon quarry, Canada. The quarry is located in the middle of the city of Montréal, but had been closed in 1981 and will not reopen in the future.
