Monohydrate minerals

Tungstite is a hydrous tungsten oxide mineral with formula: WO3·H2O. It is a secondary mineral formed by the weathering of other tungsten containing minerals. It crystallizes in the orthorhombic system in translucent yellow to yellow green masses. It is clay-like with Mohs hardness of 2.5 and a specific gravity of 5.5.

Hilgardite is a borate mineral with the chemical formula Ca2B5O9Cl·H2O. It is transparent and has vitreous luster. It is colorless to light pink with a white streak. It is rated 5 on the Mohs Scale. It crystallizes in the triclinic crystal system. Crystals occur as distorted tabular triangles and are hemimorphic, polytypes exist.

thumb | right | White vitreous crystal aggregates of the extremely rare Al mineral akdalaite from the TL (Solnechnoye Mine, Kara-Oba, Karazhal, Ulytau Region, Kazakhstan) and only one of 6 known localities worldwide. Ex Vandenbroucke Museum collection from Waregem, Belgium. Akdalaite (IMA symbol: Akd) is a very rare mineral found in Kazakhstan and has the formula . It was formerly believed to be . It is therefore the same as tohdite an artificially produced phase. Studies on the crystal structure and spectra indicate that this is an aluminium oxide hydroxide.

Gunningite is one of the minerals in the Kieserite group, with the chemical formula . Its name honours Henry Cecil Gunning (1901–1991) of the Geological Survey of Canada and a professor at the University of British Columbia.

Ancylite is a group of hydrous strontium carbonate minerals containing cerium, lanthanum and minor amounts of other rare-earth elements. The chemical formula is with ancylite-Ce enriched in cerium and ancylite-La in lanthanum.

Nuragheite is a rare natural thorium molybdate, formula Th(MoO4)2·H2O, discovered in Su Seinargiu, Sarroch, Cagliari, Sardegna, Italy. This locality is also a place of discovery of the other thorium molybdate - ichnusaite, which is a trihydrate.