Reading Room · Provenance Guide
Gold Purity Stamps
A reference manual for deciphering karat marks, parts-per-thousand fineness, and bullion stamps.
Karat Fineness Scales
Understanding purity ratios across 10K, 14K, 18K, 22K, and 24K precious metals.
- 24 Karat (999) Pure Gold · Investment Bullion
- 22 Karat (916) Traditional Crown Gold · Sovereigns
- 18 Karat (750) Luxury Watch Cases · Fine Jewelry
- 14 Karat (585) Durable American Estate Jewelry
- 10 Karat (417) Minimum Legal US Gold Standard
Assay Testing Methods
Physical touchstone acid testing, specific gravity testing, and XRF spectrometry methods.
Authentic assayer stamps protect collectors against surface plating and counterfeit hallmarks. Always look for deep, struck millesimal numbers.
Explore bullion dealers