- 23:59, 5 January 2006 diff hist -23,358 AY Honor Shells - Advanced Answer Key
- 23:58, 5 January 2006 diff hist -23,369 AY Honor Shells - Advanced Answer Key added more about physical properties of nacre to end of first paragraph; added paragraph about iridescence
- 23:48, 5 January 2006 diff hist -23,880 AY Honor Shells - Advanced Answer Key "clay platelets" in picture caption changed to "aragonite platelets"
