A method of determining an age in years by measuring the concentration of
carbon-14 remaining in an organic material, usually formerly living
matter, but also water, bicarbonate, etc. The method is based on the
assumption that assimilation of carbon-14 ceased abruptly on the death of
an organism and that it thereafter remained a closed system. The method is
useful in determining ages in the range of 500 to 30,000 years or 40,000
years, although it may be extended to 70,000 years by using special
techniques involving controlled enrichment of the sample in carbon-14.
Syn:radiocarbon dating; carbon dating. AGI
a. Coaly, containing carbon or coal, esp. shale or other rock containing
small particles of carbon distributed throughout the whole mass.
Fay
b. Carbonaceous sediments include original organic tissues and
subsequently produced derivatives of which the composition is organic
chemically. AGI
Cryptocrystalline diamond; compact, tough, opaque, dark-gray to black,
cleavage absent; generally in rounded masses, also in angular broken
fragments. Principal source is Bahia, Brazil, but also found elsewhere in
South America and Africa. Syn:black diamond; carbon diamond.
CF:ballas
See:carbon bit
Recovery of dissolved soluble constituents onto activated carbon due to
some form of chemical sorption at the active sites. Carbon adsorption is
particularly useful for removing gold and silver from cyanide leach
solutions or dissolved organics from process solutions. Van Zyl
a. A compound containing the acid radical CO3 of carbonic acid.
Bases react with carbonic acid to form carbonates. CF:carbonate
CTD
b. A mineral compound characterized by a fundamental anionic structure of
(CO3 )2- . Calcite and aragonite, CaCO3 , are
examples of carbonates. CF:borate; nitrate. AGI
c. A sediment formed by the organic or inorganic precipitation from
aqueous solution of carbonates of calcium, magnesium, or iron; e.g.,
limestone and dolomite. See also:carbonate rock
d. Ores containing a considerable proportion of metal carbonates.
Fay
e. Salts of carbonic acid, H2 CO3 . Henderson
See:dehrnite
Hardness of water, expressed as CaCO3 , that is equivalent to the
carbonate and bicarbonate alkalinity. When the total alkalinity, expressed
as CaCO3 , equals or exceeds the total hardness, all the hardness
is carbonate. It can be removed by boiling and hence is sometimes called
temporary hardness, although this syn. is becoming obsolete.
Syn:hardness
a. Metallurgical process for dissolution of metal values by means of a
sodium carbonate solution. Used on high-lime ores. Ballard
b. Dissolution of uranium with an aqueous solution of sodium carbonate in
the presence of sufficient oxygen to render uranium hexavalent.
Pryor, 1
c. Tungsten autoclave dissolution.
A mineral formed by the combination of the radical (CO3 ) (super
2-) with cations; e.g., calcite, CaCO3 .
See:witherite
See:calcite
See:strontianite
A rock, such as limestone, dolomite, or carbonatite, that consists chiefly
of carbonate minerals; specif. a sedimentary rock composed of more than
50% by weight of carbonate minerals. Syn:calcareous rock
A sand derived predominantly from carbonate material such as corals,
mollusc shells, algae, etc. Cruickshank
a. A process of chemical weathering involving the transformation of
minerals containing calcium, magnesium, potassium, sodium, and iron into
carbonates or bicarbonates of these metals by carbon dioxide contained in
water (i.e., a weak carbonic-acid solution). Syn:carbonatization
AGI
b. Introduction of carbon dioxide into a fluid. AGI
A carbonate rock of apparent magmatic origin, generally associated with
kimberlites and alkalic rocks. Carbonatites have been variously explained
as derived from magmatic melt, solid flow, hydrothermal solution, and
gaseous transfer. AGI
a. Introduction of, or replacement by, carbonates. AGI
b. See:carbonation
A diamond bit in which thc cutting medium is inset carbon. Long
Brick usually made from crushed coke and bonded with pitch or tar.
See:carbon-14 dating