Category
page 1Hydrates
opal
thumb|alt=A map of the world displaying the countries where opal is most commonly found; Australia, Ethiopia, Brazil, Mexico and the United States of America are highlighted.|Main opal producing countries

plaster
thumb|Stucco plaster [[reliefs, such as this work at the Château de Fontainebleau, were hugely influential in Northern Mannerism. A plaster low-relief decorative frieze is above it.]]
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hydrate
In chemistry, a hydrate is a substance that contains water or its constituent elements. The chemical state of the water varies widely between different classes of hydrates, some of which were so labeled before their chemical structure was understood.
chloral hydrate
chemical compound
water of crystallization
water molecules present in a hydrated compound's crystal structure, without being covalently bound
cobalt(II) sulfate
inorganic compound
methanediol
Methanediol, also known as formaldehyde monohydrate or methylene glycol, is an organic compound with chemical formula . It is the simplest geminal diol. In aqueous solutions it coexists with oligomers (short polymers). The compound is closely related and convertible to the industrially significant derivatives paraformaldehyde (), formaldehyde (), and 1,3,5-trioxane ().
wad
porous secondary manganese oxides, mainly
terpin hydrate
group of stereoisomers
rhodium(III) nitrate
chemical compound
junitoite
Junitoite is a mineral with formula CaZn2Si2O7·H2O. It was discovered at the Christmas mine in Christmas, Arizona, and described in 1976. The mineral is named for mineral chemist Jun Ito (1926–1978).
calcium silicate hydrate
chemical compound
Friedel's salt
Calcium chloroaluminate formed by reaction of AFm hydrates with chloride ions