a. A sandstone cemented with calcite. AGI
b. A sandstone containing appreciable calcium carbonate, but in which
clastic quartz is present in excess of 50%. CF:calcarenite
Coarsely crystalline calcium carbonate. See also:calcite
Adj. Designates the calcium carbonate cement of a sedimentary rock.
Rock consisting of both calcite and dolomite crystals. AGI
Native calcium oxide, CaO, found on Mount Vesuvius, Italy. It formed from
limestone enveloped in lava and altered by the heat of the lava.
A fine-grained calc-silicate rock of flinty appearance formed by thermal
metamorphism of a calcareous mudstone, possibly with some accompanying
pneumatolytic action. See also:calc-silicate hornfels
Calcium borate, CaB2 O4 , monoclinic. White radial
aggregates in drill cores from limestone skarn, from the Ural Mountains.
Named from the composition. See also:frolovite
Said of minerals and igneous rocks containing a relatively high proportion
of calcium; the proportion required to warrant use of the term depends on
circumstances. Said of a series of igneous rocks in which the weight
percentage of silica is greater than 61 when the weight percentages of CaO
and of K2 O + Na2 O are equal. Syn:calcian
Capable of being calcined or reduced to a friable state by the action of
a. The heating of a substance to its temperature of dissociation; e.g., of
limestone to CaO and CO2 or of gypsum to lose its water of
b. Heating ores, concentrates, precipitates, or residues to decompose
carbonates, hydrates, or other compounds. CF:roasting
ASM, 1; Newton, 1
c. Heating metals at high temperatures to convert them into their oxides.
a. Ore or concentrate after treatment by calcination or roasting and ready
for smelting. CTD
b. By heating, to expel volatile matter as carbon dioxide, water, or
sulfur, with or without oxidation; to roast; to burn (said of limestone in
making lime). Fay
Gypsum partially dehydrated by means of heat, having the approximate
chemical formula, CaSO4 .«H2 O .
a. Roasting of ore in oxidizing atmosphere, usually to expel sulfur or
carbon dioxide. If sulfur removal is carried to practical completion, the
operation is termed sweet roasting; if CO2 is virtually removed,
dead roasting. Pryor, 3
b. Reducing to powder by heating. Mersereau, 2
A furnace or kiln in which ores or metallurgical products are calcined.
An orthorhombic mineral, CaB2 O4 ; in white radial
aggregates in drill cores from limestone skarn in the Urals, Russia.