Rutile is an oxide mineral composed of titanium dioxide (TiO2), the most common natural form of TiO2. Rarer polymorphs of TiO2 are known, including anatase, akaogiite, and brookite.
Celestine (the IMA-accepted name) or celestite is a mineral consisting of strontium sulfate (SrSO4). The mineral is named for its occasional delicate blue color. Celestine and the carbonate mineral strontianite are the principal sources of the element strontium, commonly used in fireworks and in various metal alloys.
Strontianite (SrCO3) is an important raw material for the extraction of strontium. It is a rare carbonate mineral and one of only a few strontium minerals. It is a member of the aragonite group.
In mineralogy, crystal habit is the characteristic external shape of an individual crystal or aggregate of crystals. The habit of a crystal is dependent on its crystallographic form and growth conditions, which generally creates irregularities due to limited space in the crystallizing medium.
Selenite, satin spar, desert rose, and gypsum flower are crystal habit varieties of the mineral gypsum.
Epidote is a calcium aluminium iron sorosilicate mineral.
Natrolite is a tectosilicate mineral species belonging to the zeolite group. It is a hydrated sodium and aluminium silicate with the formula Na2Al2Si3O10·2H2O. The type locality is Hohentwiel, Hegau, Germany.
Scolecite is a tectosilicate mineral belonging to the zeolite group; it is a hydrated calcium silicate, CaAl2Si3O10·3H2O. Only minor amounts of sodium and traces of potassium substitute for calcium. There is an absence of barium, strontium, iron and magnesium. Scolecite is isostructural (having the same structure) with the sodium-calcium zeolite mesolite and the sodium zeolite natrolite, but it does not form a continuous chemical series with either of them. It was described in 1813, and named from the Greek word, σκώληξ (sko-lecks) = "worm" because of its reaction to the blowpipe flame.
Riebeckite is a sodium-rich member of the amphibole group of silicate minerals, chemical formula Na2(Fe2+3Fe3+2)Si8O22(OH)2. It forms a solid solution series with magnesioriebeckite. It crystallizes in the monoclinic system, usually as long prismatic crystals showing a diamond-shaped cross section, but also in fibrous, bladed, acicular, columnar, and radiating forms. Its Mohs hardness is 5.0–6.0, and its specific gravity is 3.0–3.4. Cleavage is perfect, two directions in the shape of a diamond; fracture is uneven, splintery. It is often translucent to nearly opaque.
Olivenite is a copper arsenate mineral, formula Cu2AsO4OH. It crystallizes in the monoclinic system (pseudo-orthorhombic), and is sometimes found in small brilliant crystals of simple prismatic habit terminated by domal faces. More commonly, it occurs as globular aggregates of acicular crystals, these fibrous forms often having a velvety luster; sometimes it is lamellar in structure, or soft and earthy.
A botryoidal texture or mineral habit, is one in which the mineral has an external form composed of many rounded segments, named for the Ancient Greek βότρυς (bótrus), meaning "a bunch of grapes". This is a common form for many minerals, particularly hematite and malachite, which are known for frequently forming botryoidal masses. It is also a common form of goethite, smithsonite, fluorite, and chrysocolla.
Jamesonite is a sulfosalt mineral, a lead, iron, antimony sulfide with formula Pb4FeSb6S14. With the addition of manganese it forms a series with benavidesite. It is a dark grey metallic mineral which forms acicular prismatic monoclinic crystals. It is soft with a Mohs hardness of 2.5 and has a specific gravity of 5.5 – 5.6. It is one of the few sulfide minerals to form fibrous or needle like crystals. It can also form large prismatic crystals similar to stibnite with which it can be associated. It is usually found in low to moderate temperature hydrothermal deposits.
Anthodites (Greek ἄνθος ánthos, "flower", -ode, adjectival combining form, -ite adjectival suffix) are speleothems (cave formations) composed of long needle-like crystals situated in clusters which radiate outward from a common base. The "needles" may be quill-like or feathery. Most anthodites are made of the mineral aragonite (a variety of calcium carbonate, CaCO3), although some are composed of gypsum (CaSO4·2H2O).
Mesolite is a tectosilicate mineral with formula Na2Ca2(Al2Si3O10)3·8H2O. It is a member of the zeolite group and is closely related to natrolite which it also resembles in appearance.
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.
Normandite is a brittle orange brown sorosilicate mineral discovered in 1997 by Charles Normand, of Montreal. Normandite occurs in Khibiny Massif, Kola, Russia; in Poudrette quarry, Mont-Saint-Hilaire, Quebec and Tenerife, Canary Islands. It is found in nepheline syenite and in miarolitic cavities in nepheline syenite, associated with nepheline, albite, microcline, aegirine, natrolite, catapleiite, kupletskite, eudialyte, cancrinite, villiaumite, rinkite, and donnayite-(Y).
In sedimentology, a prism is a long, narrow, wedge-shaped sedimentary body. These types of sediments are typically formed during orogenic deformation; for example, the arkose detrital sedimentary rock found in fault troughs.
Gonnardite is a comparatively rare, fibrous zeolite, natrolite subgroup. Older papers claim that a complete solid solution exists between tetranatrolite and gonnardite, but tetranatrolite was discredited as a separate species in 1999. A series, based on the disorder of the silicon-aluminum in the framework, appears to exist between Na-rich gonnardite and natrolite, Na2(Si3Al2)O10·2H2O.
Bultfonteinite, originally dutoitspanite, is a pink to colorless mineral with chemical formula Ca2SiO2(OH,F)4. It was discovered in 1903 or 1904 in the Bultfontein mine in South Africa, for which the mineral is named, and described in 1932.
