![]() | |||
|
| |||
|
|
GLOSSARY
OF TERMS Metallic
minerals (or metallic ores):
Minerals that contain metallic element in their composition
(i.e. pyrite, FeS2). Industrial
minerals (or non-metallic minerals): Any rock, mineral or
other naturally occurring substance of economic value, exclusive
of metallic ores, mineral fuels, and gemstones. Chromite:
A brownish-black to iron-black mineral of the spinel group (Fe,Mg)(Cr,Al)2O4. Sulphide:
A mineral compound characterised by the linkage of sulphur with
a metal (i.e. pyrite, FeS2). Asbestos:
A commercial term applied to a group of silicate minerals that
readily separate into thin fibres that are flexible, heat
resistant and chemically inert. Umber:
A naturally occurring brown earth that consists of manganese
oxides as well as hydrated ferric oxide,
silica, alumina and lime. Ochre:
An earthy red, yellow or brown iron oxide that is used as a
pigment. Bentonite:
A soft, plastic, light-coloured rock composed essentially of
clay minerals of the montorillonite group plus colloidal silica,
and produced by chemical alteration of glassy igneous material. Aggregates:
Any of several hard, inert materials, such as sand, gravel or
crushed stone, used for mixing with a cementing or bituminous
material to form concrete, mortar or plaster. Plutonic
rocks: A rock
formed at considerable depth by crystallisation (solidification)
of magma and/or by chemical alteration. Magma
crystallisation:
Crystallisation of naturally occurring mobile molten rock
material generated within the Earth, from which igneous rocks
are thought to have been derived through solidification and
related processes. Oceanic
crust: The type
of Earth’s crust (outer layer), which underlies the ocean
basins. It is about 5-10 km thick and has a density of about 3
g/cm3. Seafloor
spreading: A
hypothesis that the oceanic crust is increasing by convective
upwelling of magma along the mid-oceanic ridges (a continuous
median mountain range extending through the North and South
Atlantic Oceans, the Indian Ocean and the South Pacific Ocean,
producing new crustal material), and the moving-away of the new
material at a rate of 1 - 10 cm per year. Chrysotile
asbestos: A
white, grey or greenish mineral which is highly fibrous and a
silky variety of serpentine.
It constitutes the most important type of asbestos. Serpentinisation:
Serpentinisation is the product of hydration of the harzburgite
(rock type), which produces a group of minerals of the
serpentinite that have the same chemical composition with the
parent rock (harzburgite), but occupy a larger volume and have a
much lower specific gravity.
Serpentinisation occurs from hydrothermal fluids that
circulate in the parent rock along fractures. Calcarenite:
A limestone consisting of predominantly (more than 50%) calcite
particles of sand size (consolidated calcareous sand). Montomorillonite:
A group of clay minerals. Terra
verde: In Cyprus
it is the mineral celadonite, which is a soft green or grey-green
earthy mineral, consisting of a hydrous silicate of iron,
magnesium, and potassium, and generally occurring in cavities in
basaltic rocks; a synonym for green earth. Generally, any of
various naturally occurring silicates used mainly as bases for
green basic dyes and pigments. Pyrite
ore bodies: A
continuous, well - defined mass of pyrite
ore. Its content is economically feasible for extraction. Ophiolite:
The group of mafic and ultramafic igneous rocks. (Mafic: This is
the composition of an igneous rock, which contains
ferromagnesian and dark-coloured minerals. Ultramafic: This is
the composition of an igneous rock, which has been composed
chiefly by mafic minerals).
|
||
| |||