Search results
Results from the WOW.Com Content Network
Rock gypsum is composed of the mineral gypsum (CaSO4·2H2O - hydrous calcium sulfate). Heating of gypsum or rock gypsum drives off the water, leaving only calcium sulfate behind (the mineral anhydrite). Adding water to anhydrite results in the formation of gypsum again. Rock gypsum, unlike rock salt, does not have a salty taste, and is softer ...
Gypsum is a common mineral, with thick and extensive evaporite beds in association with sedimentary rocks. Deposits are known to occur in strata from as far back as the Archaean eon. [16] Gypsum is deposited from lake and sea water, as well as in hot springs, from volcanic vapors, and sulfate solutions in veins.
Selenite, satin spar, desert rose, and gypsum flower are crystal habit varieties of the mineral gypsum.. All varieties of gypsum, including selenite and alabaster, are composed of calcium sulfate dihydrate (meaning that it has two molecules of water), with the chemical formula CaSO 4 ·2H 2 O. Selenite contains no selenium, the similar names both derive from Greek selḗnē (σελήνη 'Moon').
In geology, texture or rock microstructure [1] refers to the relationship between the materials of which a rock is composed. [2] The broadest textural classes are crystalline (in which the components are intergrown and interlocking crystals), fragmental (in which there is an accumulation of fragments by some physical process), aphanitic (in which crystals are not visible to the unaided eye ...
Coquina (/ k oʊ ˈ k iː n ə /) is a sedimentary rock that is composed either wholly or almost entirely of the transported, abraded, and mechanically sorted fragments of mollusks, trilobites, brachiopods, or other invertebrates. [1] [2] The term coquina comes from the Spanish word for "cockle" and "shellfish". [3] [4]
Main page; Contents; Current events; Random article; About Wikipedia; Contact us
The typical cap rock is a salt, topped by a layer of anhydrite, topped by patches of gypsum, topped by a layer of calcite. [8] Interaction of anhydrite with hydrocarbons at high temperature in oil fields can reduce sulfate (SO 2– 4) into hydrogen sulfide (H 2 S) with a concomitant precipitation of calcite. [9]
Clastic rocks are composed of fragments, or clasts, of pre-existing minerals and rock. A clast is a fragment of geological detritus , [ 1 ] chunks, and smaller grains of rock broken off other rocks by physical weathering . [ 2 ]