Historical clue formulations

• Rare finds in Minecraft — 2023-04-16
• MAY — 2020-01-06
• May birthstones — 2019-07-17
• Some sights in Oz — 2019-01-13
• Things mined in Cleopatra's Mines — 2017-07-27
• Green valuables — 2017-04-07
• Green gems — 2015-06-29
• Green gems — 2012-12-17
• May birthstones — 2011-01-18
• Green rocks — 2010-09-02
• Green gems — 2004-06-15
• Colombia is their largest producer — 2001-11-04
• Stones in crowns — 2001-05-21
• Beryl varieties — 2000-02-16
• First act of the ballet "Jewels," by George — 1999-08-26
• Some hummingbirds — 1998-11-06
• Bright green hummingbirds — 1996-11-03
• May birthstones — 1995-07-18
• May birthstones — 1995-06-05