Figure out how much gold is in a quartz gold specimen. The simplest way to test specific gravity is this, weigh the quartz gold specimen in "air" and multiply the weight by 1.9, then weight the quartz gold specimen fully submerged in "distilled water" and multiply that weight by 3.1. Minus the wet figure from the dry figure and you will get a fairly accurate specific gravity for that specimen!! You can then approximate how much pure gold is in the piece by using the numbers above. The way I do the test is to place my scale on the backs of 2 chairs so that I can put a piece of caot hanger across the weighing platten and hanging a string down from each end like a swing, and then tare out the scale to 0.00, I then attach the quartz gold specimen to the string to weigh it suspended in water.

These following numbers are specific gravity of certain materials for your reference. (thanks to Ralph Bryant, for the numbers).
Gold 19.32
Silver 10.49
Sterling Silver 10.36
Coin Silver 10.31
Copper 8.96
Nickel 8.90
Zinc 7.13
Platinum 21.45
Palladium 12.00
Tin 7.30
Lead 11.34
Iron 7.87
Aluminum 2.70
Quartz 2.66

10k yellow 11.60
10k white 11.60
14k yellow 13.40 (karats gold approximate)
14k white 13.40
18k yellow 15.50

If you have any questions about how to do this test post a reply!

mlgdave