A set of four boulder opals with interesting patterning.

• 17.49 carats (total).
• Left, 16.8 x 8.9 mm / 0.66" x 0.35".
• 3.8 mm / 0.14" thick.
• Middle left, 20 x 9.4 mm / 0.78" x 0.37".
• 3.6 mm / 0.14" thick.
• Right middle, 28.1 x 9.7 mm / 1.10" x 0.38".
• 3.5 mm / 0.14" thick.
• Right, 26.8 x 10.1 mm / 1.05" x 0.39".
• 4 mm / 0.15" thick.
• Natural solid boulder opals.
  
• Mined by Sue at her Yaraka opal mine in Queensland, Australia.
• Lower commercial grade.