An overview of gems and gemmology of Pakistan.

1. GEM STONE INDUSTRY OF PAKISTAN
Sundas Zahid
Department of Earth & Environmental Sciences,
Bahria University, Islamabad

2. CONTENTS
• Identification Tools
• Gemstone Treatments
• Gemstone cutting and polishing
• Occurrences of gemstones
• Emerald
• Aquamarine
• Tourmaline
• Topaz
• Miscellaneous Gemstones
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3. Identification Tools
• Many gemstones are quite similar in appearance and cannot be
reliably be identified on visual appearance alone.
• The tools used by gemmologists for the identification and grading of
different gemstones, range from the simple to the high-tech and
exotic.
• Microscope
• Refractometer
• Polariscope
• UV light source
• Chelsea filter
• Spectroscope
Figure: Photograph showing Immersion Stereo Zoom
Microscope
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4. Identification Tools
Figure: Photograph showing SpectroscopeFigure: Photograph showing PolariscopeFigure: Photograph showing Refractometer
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5. Gemstone Treatments
• Many gemstones found are of low quality or represented by the
verities of the non-popular colors.
• Gemstone are often subjected to enhancement with the purpose of
increasing their quality or transformation into more popular and
precious varieties.
• Different properties can be affected or improved by treatment
process, i.e.,
• To change depth of color,
• To improve transparency and purity,
• To increase mechanical stability and durability.
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6. Gemstone Enhancement
• Heat treatment
• Color improvement- Aquamarine, sapphire, ruby,
tourmaline
• Alter color- sapphire, amethyst to citrine, topaz,
zircon
• Improve clarity- sapphire, ruby
• Irradiation
• Kunzite- natural pink to green
• Topaz- colorless to various shades of blue
Effects of irradiation are unstable and can be
reversed by heating.
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7. Gemstone Enhancement
• Impregnation and chemical treatment
• Alter the bulk of a material, or least
penetrate the surface.
• Includes bleaches, colorless oil, wax,
polymer, and glass imp; colorless fracture
and cavity fillings, the analogous process
with colored materials; and various forms of
dying.
• Example- turquoise is often very porous and
is sealed with wax or plastic to ‘stabilize’
and improve the color.
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8. Gemstone Cutting & Polishing
• Each stone needs to be cut, shaped and polished for its greatest beauty.
• The process of cutting and polishing gems is called gem cutting or lapidary.
• A person who cuts and polished gems is called gem cutter or a lapidary
(lapidarist).
• Sawing
• Grinding
• Sanding
• Lapping
• Polishing
• Tumbling
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9. Gemstone Cutting & Polishing
• Sawing
• Grinding
• Sanding
• Lapping
• Polishing
• Tumbling
• Cabochons
• Faceted stones
• Beads and spheres
• Inlay
• Intarsia and mosaic
• Cameos and intaglios
• Sculpture
Lapidary Techniques
Lapidary Forms
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10. Occurrence of Gemstones
• Gemstone mineralization in KP, Gilgit-Baltistan and AJ&K occurs in the
Indo-Pak continental plate and in the suture zones.
• Gemstones are products of complex geological processes that have been
operating on and inside the earth for millions of years.
• Gemstones are originated from
i. Surface water (opals of Australia)
ii. Igneous hydrothermal/pneumatolytic activity (Emeralds- Colombia, Pakistan)
iii. Gem-pegmatites ( Brzail, Pakistan)
iv. Metamorphism ( Ruby- Pakistan, Myanmar(Burma); Peridot- Pakistan)
v. Gem gravels/placers (Diamond- Sri Lanka, Africa)
vi. Gemstones formed at greater depths (Peridot- Zabargad island of Egypt; Diamond-
Argyl, Western Austraila).
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11. Emerald
-a variety of the mineral beryl, colored green by trace amounts of chromium and sometimes vanadium.
- Be₃Al₂SiO₆
• Hardness: 7.50-8
• Specific gravity: 2.75-2.78
• In Asia, Swat emeralds has 23.5
million years age.
• Most of the emerald deposits
correspond to the continental
Collison tectonics, however, some
are not related to tectonic
processes, and are resulted from
the granitic intrusions (Australia).
• Total estimated reserves of 20-30
million carats.
• In Pakistan, emeralds are found at,
• Mingora, Swat Valley
• Gujar killi
• Charbagh
• Makhad
• Shamozai
• Gandao
• Barang
• Khaltaro
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12. Aquamarine
-Be3Al2Si6O18
• Hexagonal System
• Specific Gravity: 2.69- 2.73
• Hardness: 7-7.75
• In Pakistan, crystals of blue,
yellowish blue and greenish
blue, transparent to translucent
aquamarine and translucent to
opaque beryl occurs in the
pegmatite.
• It is found at;
• Gabor-o Bakh
• Manour (Garamchasma)
• Matak An (Rumboor)
• West of Brumburete Vally of
Chitral District
• Sumaiyar of Nagar area
• Dache
• Drot of Shengus
• Bulochi in the Gilgit Baltistan areas
of Pakistan.
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13. Tourmaline
-(Li,Na)HAl6B2Si4O21.
• Varieties of tourmaline one the
basis of color;
• Indicolite (blue or bluish-green)
• Rubellite (red)
• Bicolor or tricolor
• Watermelon tourmaline (red central
core surrounded by green)
• Schorl (black)
• Dravite (brown)
• Chrome-tourmaline (vivid green )
• Achroite (colourless)
• Hardness: 7-7.5
• Specific Gravity:
• In Pakistan, black, blue and
greenish blue tourmaline crystals
were found in simple and complex
pegmatites.
• Tourmaline bearing pegmatites are
in;
• Stak Valley( Stak Nala),
• Shigar Valley.
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14. Topaz
- Al2SiO4(F, OH)2
• Hardness: 8
• Colors: brown, yellow, orange,
sherry, red and pink.
• In Pakistan, colorless and yellowish
golden topaz is found in
pegmatites of the Gilgit-Baltistan
areas,
• Pink topaz of Katlang of Mardan
District, is very rare because it is
the only known naturally deep red
or deep pink topaz in the world.
• Katlang-Mardan
• Shamozai- Mardan
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15. Miscellaneous Gemstones
Gemstone Location Occurrences /Associations
Spinel Hunza Found along with rubies and sapphires
Visuvianite (idocrase) Sp-Darra, Dabar and Maizar in
Mohamand Agency
Found in serpentines or rocks from contact metamorphism (
limestone and dolomite),
Rodingite Hiru Shah, Malakand Agency Occurs in association with ultramafic rocks
Quartz Chitral district and Northern
Areas of Pakistan
Gem-pegmatites
Zircon 20 km south of Chilas Found in quartz calcite veins in schists and gneisses
Rutile Silai Patti-Kolangi south of Kot Associated with hydrothermal quartz veins
Azurite Giligit Associated with chalcopyrite, malachite and bornite in
metavolcanics
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16. REFRENCES
• Gems and gemmology in Pakistan /​ by Tahseenullah Khan and Allah
Bakhsh Kausar ; issued by Imran Khan, Director General, Geological
Survey of Pakistan.
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