A–Z Mineral Library/Fossil Clam Shell

Fossil Clam Shell

Fossil Clam Shell Jasper (Pakistan) Geographic Origin This jasper is primarily sourced from the Salt Range and Samana Range in Pakistan. Notable localities include Jherruk, Lakhra, and Bara Nai in Sindh, as well as regions within the Salt Range in Punjab and the Samana Range in the North-West Frontier Province (now Khyber Pakhtunkhwa). These areas are known for their rich deposits of marine fossils, including bivalves like clams. Formation and Age The fossilized clam shells within the jasper are remnants of ancient marine life. Many of these bivalve fossils date back to the Eocene epoch, approximately 50 million years ago, corresponding to the Drazinda Formation in Khyber Pakhtunkhwa.

This period was characterized by warm, shallow seas that supported diverse marine ecosystems. The fossilization process occurred as these organisms were buried by sediment, which over time, transformed into the jasper matrix through mineralization. Composition and Appearance The matrix of fossil clam shell jasper is primarily composed of chalcedony, a microcrystalline form of quartz. The fossilized clam shells are typically preserved as voids or mineralized remains within the chalcedony, often filled with calcite or other minerals.

CRYSTAL HABIT:Bivalve shell fossil
CRYSTAL STRUCTURE:Biogenic carbonate, commonly calcite or aragonite, or mineral replacement
MOHS:The matrix is primarily chalcedony, a microcrystalline variety of quartz, which has a Mohs hardness of 7
HOST ROCK:Marine sedimentary rock
ELEMENT:Water · Earth
ZODIAC:No widely established association
PROPERTIES:Not included in the supplied summary.
MINE & LOCALITY MAPS

Locations named in this mineral summary

Salt Range, Punjab, Pakistan

Samana Range, Khyber Pakhtunkhwa, Pakistan

Sindh, Pakistan

Maps identify the mines, districts and geographic localities named in the supplied summary. Where exact mine coordinates are unavailable, the map represents the broader named area.