What is the best instrument used to find out the specific gravity of gemstone?
A gemmologist can measure the relative density (specific gravity) of a gemstone using specific gravity liquids, direct measurement (Hanneman Balance), a water displacement method, or a one-pan or two-pan balance.
What do Jewellers use to pick up gemstones?
Pushers, bezel rollers and burnishers
The pusher is a useful jewellery stone setting tool for ensuring the prongs are securely held in place over the stone. To use simply apply a small amount of pressure to push the claws or bezels are over the stone.