Commodity – Gemstone
Country – India
Region – Asia
Reconnaissance Due Diligence for Coloured Gemstone in Vishakhapatnam
Geovale carried out an exploration program comprised assessment by way of Geological-structural mapping the prospect, bulk sampling from the source rock, processing of the samples to recover gemstone and assessment of their grade and value.
Geovale executed the following exercise in the project.
Geological Litho-structural mapping & sample location planning:
Detail large scale mapping (1:1000/500) of the outcrops and mine pit face were carried out to establish the source rock and their occurrence, structure, style of gemstone mineralization and interrelationship with host rock geology. Accordingly location for sample collection zone was planned.
Sample collection by pitting and trenching:
Bulk sample were collected by making pits and trenches in colluvium zone (Target gemstone- Alexandrite) and another set of bulk sample were collected by Jack hammer from Chrysoberyl bearing Pegmatite body.
Processing of samples and recovering of Gemstones:
All the collected samples were processed manually (Washing, drying, sieving, picking and storing) at the site and Gemstones were recovered, preserved for further resource assessment. And 2nd stage fine processing was accomplished in processing plant comprising Crushing (by Jaw and roll crusher), Screening, Jigging (Plunger and Garrytz) and drying. Recovering of gemstones was furnished from jigged concentrate materials. A microscope studies were also made on heavy concentrate materials for detail study on Gemstone bearing source rock composition.
Gemstone resource assessment of the prospects and evaluation on grade of gemstone