Historical clue formulations

• Crystalline structure — 2022-08-21
• Arrangement of atoms in a crystal structure — 2013-06-29
• Pie crust pattern — 2009-07-16
• Gazebo wall — 2005-07-09
• Electrical tower structure — 2004-09-04
• Framework — 2004-03-07
• Gazebo framework — 2002-02-08
• Crisscross pattern — 2000-03-28
• Grating pattern — 2000-02-11
• Trellis — 1994-06-22