Historical clue formulations

• Green gemstone — 2025-08-31
• One of the few gemstones that naturally occur in a single color (olive green) — 2021-02-12
• Birthstone for most Leos — 2018-10-24
• Green gemstone — 2011-04-10
• Olivine variety — 2007-03-30
• Olivine variety — 2006-11-24
• Yellowish green birthstone — 2006-05-16
• Green gem — 1999-07-11
• August birthstone — 1997-11-18