| Points from June McKenzie's very interesting and useful talk at our March General Meeting on Selection & Preparation of Stones for Cabochon Competitions:- - Know what stone has been nominated for the competition
- Select your material carefully
- Choose only the best quality stone
- Look at it closely- when wet, dry, in good light, at all angles. Use a 10 X magnifier
- Note any flaws, chips, etc
- Lay template carefully to avoid the flaws, etc. then mark outline carefully
- Cut with trim saw. Allow a bit around edge as a precaution
- Check again with the 10 X. to see which side is best for front face?
- Note : Stripes in a stone are best if they are placed diagonally across the cab.
| GEMSTONE MATERIALS SUITABLE FOR TUMBLING | | Stones of similar hardness can be tumbled together: | | Group 1 | | | Agate of all types | Bloodstone | | Chalcedony | Chrysoprase | | Carnelian | Beach Pebbles | | Jasper | Petrified Wood | | Group 2 | | | Amethyst | Aventurine | | Sodality | Tiger Eye | | All Quartz group | (Rose, Green, Canary, Milky, Rutilated, Citrine, Smoky, Clear) | | BUT Opal, Malachite and Rhodonite - each should be tumbled separately | | Rhodochrysite is very soft and should not be tumbled with harder materials but it can be combined with Goldstone. | | Other stones suitable for tumbling: | | Amazonite | Chert | | Lapis Lazuli | Prehnite | | Opalised Wood | Abalone Shell, Aragonite |
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