This document discusses the formation, properties, types, distribution, and uses of mica. It notes that India dominates the global mica market, exporting mainly to the US, Japan, Germany and other countries. The key points are: - Mica forms from magmatic solutions in pegmatites and has a sheet structure composed of silicon and aluminum tetrahedra. - The main types are muscovite, phlogopite, biotite and lepidolite. India's largest deposits are in Andhra Pradesh, Rajasthan, Jharkhand and Odisha. - Mica has a range of industrial and commercial uses including insulation, pigments, and cosmet

1. ECONOMIC
GEOLOGY
FORMATIONANDECONOMICIMPORTANCE
OFMICA
PRESENTED BY
M.PREM[TEAM 5]

2. INTRODUCTION
◦ India dominated the world market in mica ever since the
demand of mica in electrical industry has become
indispensable.
◦ The world depends on India for quality mica sheets and
splitting.
◦ The USA, Japan, Germany, Russia, Belgium, Poland,
France and Czechoslovakia are principal countries where
India is exporting mica.
◦ India is the leading producer of sheet mica, while USA is
the principal producer of scrap mica.

3. PROPERTIES OF MICA
◦ Mica belongs to sheet silicate(phyllosilicate) .
◦ All sheet silicates have atomic structures composed of
sheets(layers) of 𝑆𝑖, 𝐴𝑙 𝑂4 tetrahedra with alkalies and other
metals between.
◦ Possess well developed BASAL cleavage.
◦ General formula for micas is
𝐾(𝐴𝑙, 𝑀𝑔, 𝐹𝑒)2−3(𝐴𝑙𝑆𝑖3𝑂10)(𝑂𝐻)2.
◦ So, we can describe most mica compositions in terms of
three end members:
1. Muscovite
2. Annite
3. Phlogopite

4. PHYSICAL PROPERTIES OF MICA
Color
Purple, rosy, silver, gray
(lepidolite)
Dark green, brown, black
(biotite)
Yellowish-brown, green-
white (phlogopite)
Colorless, transparent
(muscovite)
Cleavage Perfect
Fracture Flaky
Mohs scale hardness
2.5–4 (lepidolite)
2.5–3 biotite
2.5–3 phlogopite
2–2.5 muscovite
Luster Pearly, vitreous
Streak White, colorless
Specific gravity 2.8–3.0
Diagnostic features Cleavage

5. TYPES OF MICA
MINERAL NAME COMMERCIAL NAME CHEMICAL COMPOSITION
MUSCOVITE Potassium mica(White mica, ruby mica) 𝐻2𝐾𝐴𝑙3(𝑆𝑖𝑂4)3
PARAGONITE Sodium mica 𝐻2𝑁𝑎𝐴𝑙3(𝑆𝑖𝑂4)3
PHLOGOPITE Magnesium mica (Amber mica) 𝐻2𝐾𝑀𝑔3𝐴𝑙(𝑆𝑖𝑂4)3 𝑤𝑖𝑡ℎ 𝑓𝑙𝑢𝑜𝑟𝑖𝑛𝑒
BIOTITE Magnesium-Iron mica (Black mica) 𝐻2𝐾(𝑀𝑔, 𝐹𝑒)3(𝐴𝑙, 𝐹𝑒)(𝑆𝑖𝑂4)3
LEPIDOLITE Lithium mica (𝑂𝐻, 𝐹)2𝐾 𝐿𝑖 𝐴𝑙2(𝑆𝑖3𝑂10)
ZINWALDITE Lithium-Iron mica(Lithium biotite) Li,Fe,K,F in addition to Al and
𝑆𝑖𝑂2
ROSCOELITE Vanadium mica V,Mg,Fe in addition to Al and 𝑆𝑖𝑂2

6. MODE OF OCCUERRENCE
MINERAL OCCURRENCE
MUSCOVITE Silicic pegmatites, mostly with granitic intrusive
PHLOGOPITE From quartz free pegmatites
BIOTITE From metamorphic rocks-biotite-schists
LEPIDOLITE
AND
ZINWALDITE
Restricted to granitic pegmatites
The Zoned or Composite pegmatite with a central quartz core, followed by a zone of pegmatite with quartz,
felspar, and mica, and a mica zone at the contact of the pegmatite-vein and the country rock.

7. SCHEMATIC STRUCTURE OF THE
PEGMATITE

8. ORIGIN
◦ Mica has been formed from magmatic solutions in the pegmatite.
◦ From an Igneo-aqueous deposit or hydrothermal replacement of earlier minerals.
◦ The fluids responsible for the formation of mica-pegmatite, were rich in volatiles
(𝐻2𝑂, 𝐹, 𝐵 𝑒𝑡𝑐)and (K, Na, Li, Al and Si).
◦ It has been suggested that the formation of pegmatites is favored in a geological setting
where the mica-schist, country rock, has metamorphosed under AMPHIBOLITE-
facies conditions.
◦ The origin of phlogopite mica is different from that of muscovite where the former
forms under the action of gases, vapors and aqueous solutions of granitic magma on
magnesium rich host rocks, dolomitized limestones and dolomites.
◦ Under the action of magma pure limestone re-crystallized into marble, and dolomitized
limestones turn into diopside rocks.

9. GEOLOGICAL DISTRIBUTION OF MICA
IN INDIA
• Mica is widely distributed in India, the
minerals bearing Mica is found in the states
of Andhra Pradesh, Maharashtra, Jharkhand,
Odisha, Rajasthan, etc.
• State-wise total resource distribution of Mica
is as follows:-
• Andhra Pradesh leads with 41% share in the
country’s total resources followed by
• Rajasthan (21%)
• Odisha (20%)
• Maharashtra (15%)
• Bihar (2%) and
• The remaining 1% is in Jharkhand and Telangana
together.

10. Andhra Pradesh:
• Andhra Pradesh is the largest mica producing state of India. In Andhra
Pradesh. Nellore district produces the best quality mica.
• Vishakhapatnam, West Godavari, and Krishna are other important mica-producing
districts.
Rajasthan:
• Second largest producer.
• In Rajasthan, the mica belt extends for about 320 kms from Jaipur to Bhilwara and
around Udaipur.
• Bhilwara district located in this belt is the most imported producer of Mica.

11. Jharkhand:
• Third largest producer.
• Mica is found in a belt extending for about 150 km in
length and 32 km in width from the Gaya district of Bihar
to Hazaribagh and Koderma districts of Jharkhand. This
Mica belt runs in an East-West direction. This belt
contains the richest deposits of high-quality ruby mica.
• Kodarma (largest reserve of mica in the world), Giridih, and
Domchanch are the chief collecting centers (located in this
belt) where Mica is processed.
• Apart from this Munger in Bihar also have sufficient mica
deposits.
• The main centres of mica production in this belt are
Kodarma, Dhorhakola, Domchanch, Dhab, Gawan, Tisri, Chakai
and Chakapathal.

12. Karnataka:
• Mica deposits occur in Mysuru and Hasan districts of Karnataka.
Tamil Nadu:
• In Tamil Nadu, Coimbatore, Tiruchirappalli, Madurai and Kanyakumari districts.
Kerala:
◦ In Kerala, Mica deposits are found in Alleppey district.
Maharashtra:
• Ratnagiri in Maharashtra has rich mica deposits.
West Bengal:
• Purulia and Bankura in West Bengal are known for mica deposits.

13. USES OF MICA
Mica is a naturally occurring stone that directly applies to a set of minerals containing
silica in its highest form. This mineral is mostly used in gypsum wallboard combined
compound where it acts as wadding and prevents cracking. There are a variety of
uses of this mineral such as:
• It is used in paints as a pigment extender and also helps to brighten the tone of colored pigments.
• In the electrical industry the same as thermal insulation, and electrical insulators in electronic
equipment.
• Its shiny and glittery appearance makes it ultimate for toothpaste and cosmetics.
• The high thermal resistance allows it to be used as an insulator in various electronics.
• MICA SHIELDS or Gauge Glass Mica can be used to secure the liquid level gauges from corrosive
and acidic solutions.