Description: Mica is a naturally occurring mineral, based on a group of silicate minerals composed of varying amounts of aluminum, potassium, magnesium, iron and water having thin sheet-like or plate-like structure with different composition and physical properties. All Mica form flat six-sided monoclinic crystals with a remarkable cleavage in the direction of large surfaces, which permits them to be easily cleaved into optically flat films. When cleaved into thin films, they remain tough and elastic even at high temperatures.
Occurrences: Mica minerals make some rocks sparkle! They are often found in igneous
rocks such as granite and metamorphic rocks such as schist. They sparkle
because light is reflected on their flat surfaces, which are where the mineral
breaks along its plane of cleavage. These minerals break so easily along their
cleavage that some crystals have broken into many thin layers that look like
the pages of a little book. Colonial Americans used the “pages” of large mica
crystals as glass for windows.
Types: Mica is also known as Muscovite, Biotite, Phlogopite, and
Lepidolite
Muscovite, commonly known as white mica, is a member of the mica family of
minerals. The mica minerals all share the property of perfect basal
cleavage, which means that layers of mica can be peeled off of a mica crystal
in very thin sheets. It is especially easy to peel off large numbers of
paper-thin sheets from a muscovite crystal. Consequently, crystals of
mica, like the one shown above, are often referred to as books of mica.”(Roger
Weller) Muscovite can be found in many colors such as white, yellow, silver,
green and brown.
Biotite is also known as black mica. It can be peeled off of a large
crystal in thin layers but with more difficulty than peeling muscovite (white
mica). Biotite does not have economic value because it lacks the
transparency and electrical insulating properties found in muscovite”(Weller).
The typical black to brown color of biotite is characteristic although it is
difficult to distinguish brown biotite from dark brown phologopite. Biotite and
phlogopite are end members in a series that is dependent on the percentage of
iron. Biotite is iron rich and phlogopite is iron poor. Biotite also has a
layered structure of iron magnesium aluminum silicate sheets weakly bonded
together by layers of potassium ions. These layers make the perfect cleavage.
When biotite crystals are weathered they can appear to be what we know as
“fool’s Gold”, a golden yellow mineral with a nice sparkle.
Phlogopite is a more rare member of the mica group not well
known even by many mineral collectors. It has and still is being mined for its
heat and electrical insulation properties, which are considered superior to
other micas. Phlogopite, like all other micas, has a layered structure of
magnesium aluminum silicate sheets inadequately bonded together by layers of
potassium ions. These potassium ion layers produce the perfect cleavage.
Phlogopite is not considered a valuable mineral specimen.
Lepidolite is a new form of mica that has only been on the
market in large quantities for only a decade. This newer form of mica is a
lithium ore that forms only in granitic masses that contain an ample amount of
lithium. Lepidolite may be found in many different colors ranging from violet
to pale pink or white and rarely gray or yellow.
Locations: Mica can be obtained from the following area of Nassarawa state viz:
Akwanga, Karu, Kokona, Toto, Nasarawa Eggon. Mica is also found in the
following states of Nigeria viz: Bauchi, Benue, Borno, Kastina, Kebbi, Kogi,
Ogun, Osun, Cross River, Plateau and FCT.
Mica Specifications:
·
Diameter--1/2 inch up
·
Quality requirements: Exportable Mica regardless of the type must be:
·
Dry
·
Clean
·
No sands
·
No stones
·
No mud or mud stain
·
Good tensile strength
Uses of Mica:
Mica can be used in many household products:
Mica can be used in many household products:
1.
It acts as a filler and extender. It provides a smoother consistency,
improves workability and helps to prevent cracking.
2.
Also in the paint industry; ground mica is used as a pigment extender
and facilitates suspension due to its lightweight anatomy. The ground mica also
helps prevent shrinkage and shearing of the paint film, provides increased
resistance to water penetration and weathering, and brightens the tone of the
colored pigments.
3.
3 . Sheet mica is mainly used in the electronic
and electrical industries. Sheet and block mica are used as insulators in
electronic equipment, thermal insulation, gauge “glass”, windows in stove and
kerosene heaters, decorative panels in lamps and windows, insulation in
electric motors and generator armatures, field coil insulation and magnet and
commutator core insulation.
4.
4 . Mica flakes are also used as snow in movies
or for decoration. Also you can find mica in many of your personal care items
such as toothpaste, eyeliner, concealer, nail polish, shimmer powder, lotions,
lipstick, body wash, sunscreen, shampoo, conditioner, and hair dyes.
Where can Mica be Exported
The major export markets Mica is China. Other buyers next to china include India, Canada, Malaysia, Pakistan, Bulgaria and Australia.
The major export markets Mica is China. Other buyers next to china include India, Canada, Malaysia, Pakistan, Bulgaria and Australia.
Mica Export Price: Depending on the purity of the FOB price of Mica could vary from
US200-300/MT.
Mica Local price: Depending on the purity and type of Mica, the local market price for Mica in Nigeria at
the loading point could vary from NGN10,000-NGN15,000/MT
