Historical clue formulations

• Emerald or aquamarine — 2023-02-05
• Emerald is a variety of it — 2021-04-08
• Emerald or aquamarine — 2018-07-08
• Emerald or aquamarine — 2018-05-13
• Color akin to turquoise — 2016-11-17
• Green gemstone — 2016-11-07
• Emerald, e.g. — 2013-10-27
• Green gem source — 2010-05-12
• Emerald or aquamarine — 2005-08-25
• Gem mineral — 2003-01-06