A set of two geometric boulder opals.

• 18.56 carats (total).
• Left, 22.4 x 14.6 mm / 0.88" x 0.57".
• 4.2 mm / 0.16" thick.
• Right, 21.5 x 17.7 mm / 0.84" x 0.69".
• 3.8 mm / 0.14" thick.
• Natural solid boulder opals.
  
• Mined by Sue at her Yaraka opal mine in Queensland, Australia.
• Lower commercial grade.
• Sister stones (out of the same host boulder).