A set of four small boulder opals, all with great green-blues colours.

• 5.90 carats (total).
• Left, 9 x 3.8 mm / 0.35" x 0.14".
•  3.1 mm / 0.12" thick.
• Center left, 9.5 x 7.1 mm / 0.37" x 0.27".
•   3.3 mm / 0.12" thick.
• Center right,  9.3 x 5.2 mm / 0.36" x 0.20".
•  2.8 mm / 0.11" thick.
• Right, 13.7 x 4.9 mm / 0.53" x 0.19".
• 3 mm / 0.11" thick.
• Natural solid boulder opals.
  
• Mined by Sue at her Yaraka opal mine in Queensland, Australia.
• Commercial grade.