Kashmir Gemstones from Pakistan Himalayas

Kohistan in Pakistani is the place to be in this world where gemstones are found, however, what is more outstanding is the geology which forms them. A pair of gems which are the bright green peridot of Kohistan and the rare Kashmir type sapphire Pakistan provide a wonderful chance to investigate the great forces of tectonic processes which form the Himalayan mountains. This paper explores the geology of these deposits that have resulted in the formation of these underground treasures as a result of the gradual collision of the continents.

The Northern Pakistan is the geologically significant region of the world with respect to gemstones. Kohistan peridot and Batakundi sapphire, two different types of gemstones, are some of the most remarkable treasures of it made of the same system of building the Himalayas mountains.

We are KashmirStones.com, and we deal in natural Himalayan gemstones that are sourced directly in mineral rich belts which are a direct result of the tectonic collisions.

Introduction to Himalayas

One needs to comprehend the dramatic geological environment in which the gems reside in order to understand the gems. The novel does not start in Pakistan, but instead out in the Tethys Sea, in the Cretaceous era, some 100 to 120 million years prior.

Due to a process called subduction, a chain of volcanic islands were formed in the ocean at the time which was called the Kohistan Island Arc. This arc was fundamentally a primitive deposit of oceanic crust and mantle and resembles the present day Japan or Indonesia. This island arc got stuck in between the Indian and the Eurasian plates as they started their colossal collision. It was not destroyed, but scraped off and obducted, that is, in other words, up and on to the Indian plate in the Early Paleocene epoch . The result was the preservation of a whole portion of the crust and the upper mantle of the arc, which is found to-day in the mountains of northern Pakistan. This spectacular view gives the geologists an eye into the deep earth and it is thus one of the most ideal locations to research on the processes of island arcs and how a new continental crust is formed.

Continental Collision and the Birth of the Himalayas

Approximately 50 million years ago the Indian Plate hit the Eurasian Plate. The effects of this huge influence were:

Kohistan peridot and Batakundi sapphire are both the direct effects of this geological phenomenon.

Supat Valley Peridot, Kohistan Pakistan

Peridot gemstones of gem quality occur in the Sapat mafic-ultramafic complex, which is a major component of the Kohistan Arc that was revealed around the Sapat Gali region, northeast of Naran, in the Kaghan Valley.

The peridot is not a plain igneous crystal geologically. It is created under a very specialized condition: shear zones in partially serpentinized dunite rocks. Dunite is an ultramafic rock which is virtually made solely of olivine the mineral that is made up of peridot. Such shear zones are cracks and bands of deformation formed due the huge tectonic forces of the continual collision of the continents.

The palette of peridot is not wide, but it has a brown-green shade and spectrums to yellowish-green and green itself. The most typical color of peridot that is used in jewelry is yellowish green.

One of the minerals that forms a jewel is peridot. Its chemical composition contains iron and magnesium and the attractive yellowish green colors is caused by iron. The gem is frequently found in volcanic rocks referred to as basalts that are abundant in the two elements.

Kohistan Peridot: A Himalayan Gem from Mantle

Kohistan peridot is found in ultramafic rocks including dunite and peridotite found in the Kohistan-Ladakh Arc. The Himalayan Peridot located in the Himalayan region of Pakistan, which is the Sapat Gali (Supat Valley) in the Mansehra District is internationally recognized as being one of the best sources of gem quality olivine. These stones are very valuable in their rich deep green colour and their high level of clearness.

Key Geological Features

Kohistan supat valley peridot is the material that was formed deep below the surface of the crust of the earth, this is why it is geologically incredible.

The Fluid role in the formation of gems:

These shear zones that were filled with fluids are what are considered magic in making gem-quality crystals. It has been shown that the olivine (peridot) was formed through the precipitation of the subduction-related fluids, which contained large amounts of carbon dioxide (CO2) and water (H2O) in them. These liquids were the result of the drying up of both the subdued plate and the sediment cover which mixed with the mantle rocks. They deposited the olivine crystals as they passed through the fractures forming the pockets and veins where they were mined as gemstones, which were euhedral (well-formed). These fluids had a very clear fingerprint in terms of their chemical composition.

The Kohistan peridot is forsteritic, i.e., the magnesium-rich type of olivine. It can be analyzed to be composed of Fo89 to Fo92 with some even being more magnesian (to Fo97) . It is the high concentration of magnesium that makes the gem its characteristic color. The intensity of the green color is directly proportional to the amount of iron (Fe); the more iron, the more yellowish-green is the color.

More indication of the complicated chemistry of the fluid is observed in the inclusions present in the peridot. Smaller needle-shaped crystals of a rare mineral named ludwigite [(Ti,Cr,Fe3+) (Mg,Fe2+)2 BO5) have been determined. The fact that there is ludwigite, a borate mineral, means that the hydrothermal fluids also had boron (B), in addition to CO2. This indicates a major geological process in which elements such as carbon, and boron, which were initially found on the surface of the earth are pulled down to a subduction zone and recycles to the surface to form gemstones.

Kohistan Peridot Gemological Properties:

• Color: Pleochroic (different color when viewed at different angles) and with colors varying between being pale green to yellow-greenish or olive.
• Refractive Index: a = 1.644 to 1.653, g = 1.682 to 1.684 (+-0.003) .
• Density: Ranges from 3.26 to 3.44 g/cm3 .
• Crystal Size: Crystals are usually less than 3 cm in size, although crystals can be as long as 15 cm and weigh 2 kg have been obtained.

Geology of Batakundi Kashmir Sapphire Pakistan

But not far away, at an approximate distance of half a furlong, in the valley of Kaghan, in the neighbourhood of the village of Batakundi, a quite different gemological narrative plays itself out. In this case, the host rock is not a dunite of mantle origin, but a marble. This metamorphic rock was initially limestone which was part of the cover sedimentation of the Indian continent plate.

An example of a typical metamorphic formation of gems is the formation of Batakundi sapphire (corundum, Al2O3). When the Indian plate was forced due to the collision under Kohistan Arc, the sedimentary rocks were exposed to high pressures and temperatures, which was referred to as regional metamorphism. This metamorphism was of sufficient grade to put the aluminum-bearing minerals into the unsteady condition of liberating the aluminum to mix with the oxygen and to form as corundum, the mineral form of both ruby and sapphire.

The formation conditions are preserved in the inclusions that are entraped in the sapphires. An example is that GIA scientists have discovered some inclusions of graphite (pure carbon) and feldspar in sapphires found in this part of the world. On the one hand, the origin of the gem in the marble is supported by the fact that graphite is a metamorphic mineral in the carbonates transformed into metamorphism. Feldspar indicates that the metamorphic conditions entered an area between temperature and pressure where the two minerals were both stable. There was one great stone, too, which bore a trapiche-like nature, being a frozen six-rayed star, produced by inclusions of minute particles, and needle-shaped minerals, laid along the growth form of that crystal. This is an extremely peculiar texture, and suggests most definite, even unique, conditions of growth in the Himalayan metamorphism.

Batakundi Himalayan Sapphires Characteristics:

• Host Rock: Ruby-bearing marble.
• Formation Age: The Himalaya is thought to have formed in the Miocene period, some 16 million years ago, one of the most important periods in the evolution of the Himalayas.
• Important Inclusions: feldspar, rutile needles and graphite (carbon).
• Color: Corundum may occur in any color in accordance with trace elements. Although Batakundi is famous in producing ruby (red, of chromium), there are rare violet and pink sapphires produced in the area as well.

Batakundi sapphire - Crustal formation of metamorphism

Batakundi is located in the Naran-Kaghan area of Kashmir Valley and it is located in the Himalayan metamorphic belt.

Formation Conditions

Although it was formed at varying depths than that of peridot, it has the same tectonic origin.

A Common Geology of Peridot from Kohistan and Batakundi Sapphire

The formation of the Kohistan peridot and Batakundi sapphire is different, but they are indisputably connected by the megalithic event that brought them together The Himalayan orogeny.

The Suture Zone: The two deposits are found in the geological suture zone where the Kohistan Arc was overriding the Indian plate. The peridot is located in the mantle rocks of overriding arc whereas the sapphire was produced in the metamorphic rocks that are produced on the lower plate which is the Indian plate. One is a coin of collision on the other.

The Role of Fluids: Fluids affected the two deposits, although in varying degrees. The precipitating agents of the olivine were gels in Kohistan. Fluids found in Batakundi would have been catalysts to metamorphic reaction taking part to move elements and allow the formation of large corundum grains. The flow of these fluids was a direct result of the thickness and heating of tectonics that occurred in the collision.

Time Relation: These gems are formed due to certain pulses of Himalayan tectonic. The peridot veins have an undeformed character indicating that they were created at a late stage of the orogeny possibly associated with Eocene metamorphism or the intrusion of leucogranites. The sapphires, which can be said to be approximately 16 million years old, were formed during the Miocene, the rapid uplift and unroofing period in the area . This proves the fact that gem formation did not take place in one process but a series of processes that took place in various stages of the mountain-building process.

Comparison of Himalayan Peridot and Batakundi Kashmir Sapphire

Side-by-Side Geological Comparison

Shared Geological Framework

According to geological survey and market research, Kohistan and Batakundi are situated in the Himalayan, Karakoram and Hindukush mountain ranges in Pakistan which are known throughout the world as the source of high quality gemstones. Although Kohistan is rich in its minerals and it has large deposits of green stones, Batakundi is specifically known to produce the Kashmir type sapphires and rubies which are usually of a peculiar purple-pink color.

Why Himalayan Origin Matters in Gemstones?

Himalayan origin plays an essential role in gemology, as the geological, metamorphic and tectonic activities that took place in the formation of the mountain range (collision of India and Asia) produce remarkably rare, high quality, and unique in chemistry gemstones, such as Kashmiri sapphires, rubies, and beryl. These are commonly indicators of higher value, unusual colour, and unusual inclusions and as such they are treasures of rare, in some cases depleted, geologic settings.

As access becomes more difficult, well-documented origin gemstones increase in importance for collectors and investors.

KashmirStones Commitment

We offer:

• Gemstones in their original form.
• Himalayan direct-source material.
• Geological transparency
• Professional documentation

Look through our stock of Kohistan peridot and Batakundi sapphire to possess a fragment of Himalayan geology.

Common FAQs about Himalayan Stones

Why is this geological relationship important to you?

By buying a Kohistan peridot or a Batakundi sapphire, you are not merely buying a gemstone.

What You Are Buying Kashmir Stones?

Kohistan peridot is mantle born brilliance that is hardly experienced worldwide.

Batakundi sapphire brings Himalayan metamorphic elegance which can be related to the same geological formation that caused the Kashmir sapphires to be a legend.

Conclusion

Not only are the peridot of Kohistan, and the sapphire of Batakundi, beautiful gems; but they are also the representatives of the far-off past, and each of them, though telling a different story, a complement to the other, has a bearing upon the origin of the Himalayas. The peridot tells of fluids oozing through the mantle rocks of a primeval island arc, the sapphire tells of the intense metamorphism which changed the continental margin when it was pulled deep into the earth. They are all geological parts of a great geological network, providing a concrete connection with the active and powerful energies that still work to form the "Roof of the World." To both geologists and gem lovers, the mountains of Northern Pakistan still are an open book where each facet-cut stone is a window leading into the amazing interior of our planet.

References: 

1. https://www.himalayanclub.org/hj/2/3/the-gem-stones-of-the-himalaya/#:~:text=These%20rocks%20are%20found%20in,alone%20gems%20can%20be%20cut. 
   
2. https://www.mindat.org/locentry-799799.html
3. https://www.gia.edu/peridot-description

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