Elements and Performance Criteria
- Select opal for cutting as an opal doublet or triplet.
- Flatten opal and base.
- Flatten opal on marked side (this will be the best play of colour side) until surface is free of potch and impurities and completely down to the colour bar using appropriate equipment.
- Select backing materials and flatten.
- Lap opal and base until flat satin finish is obtained.
- Clean and dry opal and base.
- Cement components together.
- Blacken flattened surface with appropriate blacking agent.
- Mix adhesive to manufacturers' instructions.
- Ensure stone is cemented with the best colour face down.
- Cement flattened surfaces together eliminating excess adhesiveness and air bubbles.
- Allow adhesive to harden following manufacturers' instructions.
- Preform opal doublet.
- Convert doublet to triplet.
- When working with a very thin opal layer, manufacture a triplet.
- Lap the colour surface of the opal until a thin layer of opal remains on the backing.
- Clean and dry stone.
- Cement manufactured triplet top or preferred alternative to the opal surface eliminating excess adhesive and air bubbles.
- After curing, grind the stone to expose both joins.
- Follow OHS principles when operating machinery.