Historical clue formulations

• Standards of purity — 2024-03-23
• Some bars have 24 of them — 2023-07-26
• Gold standards — 2021-11-10
• Chain units, maybe — 2017-11-17
• Gold standards — 2017-03-06
• Gold standards — 2016-09-27
• Gold standards — 2014-12-17
• Gold standards — 2007-08-07
• Purity units — 2004-01-20
• Gold count — 1999-01-31