999 gold
999 gold means gold with a fineness of 999 parts per thousand, commonly described as 99.9 percent gold.
Why it matters
It is often used for modern bullion bars and some bullion coins where the value is intended to track fine-gold content closely.
What to check
Do not compare 999 gold with 22 carat or 18 carat gold by gross weight alone. Fine-gold content is the useful comparison.