Elements and Performance Criteria
- Set up faceting equipment.
- elect, pre-shape and dop selected opal piece.
- Grind, sand and polish pavilion.
- Place dopped stone in quill and aligned to create girdle.
- Grind girdle to desired shape on medium to fine lap.
- Grind main facets at main angle on medium to fine lap.
- Grind girdle break facets at girdle break angle on fine lap.
- Grind culet facets at culet angle on fine or pre-polish lap.
- Fine lap, pre-polish and polish all pavilion facets including girdle.
- Transfer stone.
- Grind, pre-polish and polish crown.
- Place girdle facet on lap at 90º, index setting 64 or 96 and lock quill.
- Grind girdle break facets at break angle establishing girdle thickness, on a medium to fine lap.
- Grind main facets at main angle on fine lap.
- Cut table facet on fine lap, to 40% of total width of stone.
- Pre-polish all crown facets.
- Grind star facets using pre-polish lap.
- Polish all facets.
- Remove stone from dop and clean.