If you mean on gold bars on eBay and the internet, 100 mills means "very very thin plating".
No one is quite sure what mills refers to there, but some suspect it means 1/10,000 of an inch thick.
These bars are worth very little, and the only reason you should consider getting them is as props for a movie or fakes to mislead a thief. Don't pay more than a couple dollars for them, as they are basically decorative.
In U.S. measurement a mill refers to one onethousanth of an inch (.001)
100 mills would be one tenth of an inch (.01). In metric it means something else
which can be confusing.
Correction, my mistake: one tenth of an inch is 0.1, one hundredth is .01
1. Measure the thickness of a stack of 100 index cards 2. Divide the answer from 1 by 100
100 mills layered Gold or Silver is only plating of 1.2 microns or more thick and has a low value on the open market.
My 6th grade text book says it is 100 km thick
If you are talking about the fake bullion on ebay, it's extremely thin. In electronics, a "mil" is 1/1000th of an inch.
There are 1000 mills in a litre, so in half a litre there are 500 mills.
100 mills
over 100 flour mills
100
stack up 100 of the same type of piece of paper, measure the thickness with a very accurate ruler, divide this thickness by 100
deceptive mesurment
100 100
3/100
0.113mm
100
1. Measure the thickness of a stack of 100 index cards 2. Divide the answer from 1 by 100
24carat
Around 100