Minerals in space group 148

carbonate mineral – CaMg(CO₃)₂

Ilmenite is a titanium-iron(II) oxide mineral with the idealized formula . It is a weakly magnetic black or steel-gray solid. Ilmenite is the most important ore of titanium and the main source of titanium dioxide, which is used as white pigment in paints, printing inks, fabrics, plastics, paper, sunscreen, food and cosmetics.

Phenakite or phenacite is a fairly rare nesosilicate mineral consisting of beryllium orthosilicate, Be2SiO4. Occasionally used as a gemstone, phenakite occurs as isolated crystals, which are rhombohedral with parallel-faced hemihedrism, and are either lenticular or prismatic in habit: the lenticular habit is determined by the development of faces of several obtuse rhombohedra and the absence of prism faces. There is no cleavage, and the fracture is conchoidal. The Mohs hardness is high, being 7.5–8; the specific gravity is 2.96. The crystals are sometimes perfectly colorless and transparent, b

Willemite is a zinc silicate mineral () and a minor ore of zinc. It is highly fluorescent (green) under shortwave ultraviolet light. It occurs in a variety of colors in daylight, in fibrous masses and apple-green gemmy masses. Troostite is a variant in which part of the zinc is partly replaced by manganese, it occurs in solid brown masses.

Ankerite, also known as brown spar () is a calcium, iron, magnesium, manganese carbonate mineral of the group of rhombohedral carbonates with the chemical formula . In composition it is closely related to dolomite, but differs from this in having magnesium replaced by varying amounts of iron(II) and manganese. It forms a series with dolomite and kutnohorite.

Dioptase is an intense emerald-green to bluish-green mineral that is cyclosilicate of copper. It is transparent to translucent. Its luster is vitreous to sub-adamantine. Its formula is , also reported as . It has a Mohs hardness of 5, the same as tooth enamel. Its specific gravity is 3.28–3.35, and it has two perfect and one very good cleavage directions. Additionally, dioptase is very fragile, and specimens must be handled with great care. It is a trigonal mineral, forming six-sided crystals that are terminated by rhombohedra.

Abenakiite-(Ce) is a mineral of sodium, cerium, neodymium, lanthanum, praseodymium, thorium, samarium, oxygen, sulfur, carbon, phosphorus, and silicon with a chemical formula Na26Ce6(SiO3)6(PO4)6(CO3)6(S4+O2)O. The silicate groups may be given as the cyclic Si6O18 grouping. The mineral is named after the Abenaki, an Algonquian Indian tribe of New England. Its Mohs scale rating is 4 to 5.

Kutnohorite is a rare calcium manganese carbonate mineral with the formula in the dolomite group of minerals. It forms a solid solution with the other group members dolomite and ankerite. The mineral was originally spelt "kutnahorite" but "kutnohorite" is the current IMA-approved spelling.

Chalcophyllite is a rare secondary copper arsenate mineral occurring in the oxidized zones of some arsenic-bearing copper deposits. It was first described from material collected in Germany. At one time chalcophyllite from Wheal Tamar in Cornwall, England, was called tamarite, but this name is now discredited (not to be confused with the amphibole mineral taramite, which is quite different). At Wheal Gorland a specimen exhibiting partial replacement of liriconite, , by chalcophyllite has been found. The mineral is named from the Greek, chalco "copper" and fyllon, "leaf", in allusion to its com

Benstonite is a mineral with formula Ba6Ca6Mg(CO3)13. Discovered in 1954, the mineral was described in 1961 and named after Orlando J. Benston (1901–1966).

Eucryptite is a lithium-bearing aluminium silicate mineral with formula LiAlSiO4. It crystallizes in the trigonal - rhombohedral crystal system. It typically occurs as granular to massive in form and may pseudomorphically replace spodumene. It has a brittle to conchoidal fracture and indistinct cleavage. It is transparent to translucent and varies from colorless to white to brown. It has a Mohs hardness of 6.5 and a specific gravity of 2.67. Optically it is uniaxial positive with refractive index values of nω = 1.570 – 1.573 and nε = 1.583 – 1.587.

Pyrophanite is a manganese titanium oxide mineral with formula: MnTiO3. It is a member of the ilmenite group. It is a deep red to greenish black mineral which crystallizes in the trigonal system.

Shigaite is a mineral with formula NaAl3(Mn2+)6(SO4)2(OH)18·12H2O that typically occurs as small, hexagonal crystals or thin coatings. It is named for Shiga Prefecture, Japan, where it was discovered in 1985. The formula was significantly revised in 1996, identifying sodium as a previously unknown constituent.

Davidite is a rare earth oxide mineral with chemical end members Lanthanum (La) and Cerium (Ce). It exists in two forms: Davidite-(La) discovered at Radium Hill mine, South Australia in 1906 and named by Douglas Mawson for Australian geologist Tannatt William Edgeworth David (1858-1934). Davidite-(Ce) first described in 1960 from Vemork, Iveland, Norway.

Susannite is a lead sulfate carbonate hydroxide mineral. It has the formula Pb4SO4(CO3)2(OH)2. Susannite is the higher temperature phase of the two and forms above 80 °C when fluids oxidize the lead ore deposits. It is trimorphous with leadhillite and macphersonite.

Geikielite is a magnesium titanium oxide mineral with formula: MgTiO3. It is a member of the ilmenite group. It crystallizes in the trigonal system forming typically opaque, black to reddish black crystals.

Tachyhydrite is an unstable mineral, a hydrous chloride of calcium and magnesium with formula: CaMg2Cl6·12H2O. It is a rare component of marine evaporite salt deposits. Upon exposure to moist air it rapidly deliquesces and dissolves.

Tusionite is a rare colorless to transparent to translucent yellow brown trigonal borate mineral with chemical formula: MnSn(BO3)2. The mineral is composed of 18.86% manganese, 40.76% tin, 7.42% boron, and 32.96% oxygen. It is a late stage hydrothermal mineral and occurs rarely in granite pegmatites in miarolitic cavities.

Cleusonite is a member of the crichtonite group of minerals with the chemical formula . This group of minerals contains approximately thirteen complex metal titanates. The structures of minerals of this group is complicated by frequent fine-scale twinning and metamictization due to radioactive elements. The crichtonite group consists of members of related mineral species of the type A{BC2D6E12}O38 which are characterized by their predominant cations (as seen in crichtonite (Sr), senaite (Pb), davidite (REE + U), landauite (Na), loveringite (Ca), lindsleyite (Ba), and mathiasite (K).

Akimotoite is a rare silicate mineral in the ilmenite group of minerals, with the chemical formula . It is polymorphous with pyroxene and with bridgmanite, a natural silicate perovskite that is the most abundant mineral in Earth's silicate mantle. Akimotoite has a vitreous luster, is colorless, and has a white or colorless streak. It crystallizes in the trigonal crystal system in space group R. It is the silicon analogue of geikielite (MgTiO3).

Millosevichite is a rare sulfate mineral with the chemical formula Al2(SO4)3. Aluminium is often substituted by iron. It forms finely crystalline and often porous masses.

Löweite is a rare evaporite sulfate mineral with the chemical formula Na12Mg7(SO4)13·15H2O. It occurs in marine salt deposits, saline playa crusts, and occasionally as a volcanic sublimation product. The mineral crystallizes in the hexagonal–trigonal system (space group R3) and is typically colorless, though it may appear reddish-yellow due to impurities. Löweite has a vitreous luster and a Mohs hardness of 2.5–3.

Loveringite is a rare metallic oxide mineral of the crichtonite group with the chemical formula . It is a late-stage magmatic mineral, formed in the residual melt of mafic layered intrusions in either the olivine-chromite, pyroxene, or plagioclase-rich layers.

Allendeite, Sc4Zr3O12, is an oxide mineral. Allendeite was discovered in a small ultrarefractory inclusion within the Allende meteorite. This inclusion has been named ACM-1. It is one of several scandium rich minerals that have been found in meteorites. Allendeite is trigonal, with a calculated density of 4.84 g/cm3. The new mineral was found along with hexamolybdenum. These minerals, are believed to demonstrate conditions during the early stages of the Solar System, as is the case with many CV3 carbonaceous chondrites such as the Allende meteorite. It is named after the Allende meteorite

Tancaite-(Ce) is a very rare molybdate mineral with the formula FeCe(MoO4)3•3H2O. It was found in Punta de Su Seinargiu locality on Sardinia, Italy. Red crystals of tancaite-(Ce) resemble modified cubes, but the mineral is trigonal (space group R-3). The type locality of tancaite-(Ce) is also a place of discovery of other molybdate minerals, including thorium molybdates ichnusaite and nuragheite.

Dessauite-(Y) is a mineral member of the crichtonite group with the formula . It is associated with derbylite, hematite, rutile, karelianite, siderite, and calcite. Founded in the Buca della Vena Mine, Tuscany, Italy, the mineral was called dessauite in honor of professor Gabor Dessau (1907–1983).