Specific gravity Specific gravity (SG) is a measure of the density of a substa…
Read moreWhen the need arises to identify or value a gem, it is sent to a professional …
Read moreThe origins of rocks, minerals, and gemstones Rocks and minerals are created in…
Read moreMinerals Most gems are cut crystals of minerals. A mineral is defined as a nat…
Read moreThe precious metals and gemstones that have been used for decoration and trade…
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