Historical clue formulations

• Rock with bands — 2025-07-18
• Banded metamorphic rock — 2017-05-05
• Rock whose name sounds good? — 2016-06-12
• Banded rock — 2016-04-10
• Rock with colored bands — 2014-11-21
• Layered rock — 2009-04-12
• Banded rock — 2007-10-21
• Banded rock — 2001-12-01
• Rock variety — 1998-11-29
• Sparkly rock — 1998-09-28
• Granitelike rock — 1994-11-17