What is the purity of gold at 100 mills?

Answer 1

That is a measure of Gold weight, not gold purity.

A bar described as "1oz 100 mills 24k GOLD!!!!" contains one ounce of worthless scrap metal, plated with gold with only 100 millionths (0.0001 of an troy oz of gold). In plating, " MIL " stands for thousands of an inch but " MILL " is mass and is millionths of an troy oz (0.0001). So if Gold is trading at $1,300 per troy oz 100 mill is 0.0001 X $1300 = $0.13 worth of gold.

eBay seems to be full of these sorts of items. The terms "solid" (meaning full of scrap metal, not hollow) and "pure gold" (meaning the plating is pure, not the scrap metal) are often used misleadingly, while the term "plated" almost never appears. Gold plated items are generally almost worthless; for example, a 1oz 100 mill plated-gold bar might sell for $10 on a good day, while a 1oz solid gold bar currently sells for at least $1000.

Answer 2

Gold at 100 mills is not pure gold; it is a thin layer of gold applied to a base metal such as copper or brass. The gold layer is about 0.1% pure.

Answer 3

.002%