Amber as faceting material |
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| Physical properties | Optical properties | |||||
| (C10H16O)n - Organic | Amorphous | |||||
| Hardness 1½ - 2½ | Yellow nuances. Redbrown. Rarely with a green or blue sheen due to "Tyndall-effect". | |||||
| Density 1,05 - 1,10. Floats in concentrated saltwater. | Refractiveindex 1,54 - 1,55. | |||||
| Conchoidal to earthy fracture. Soft to brittle. Some Amber may be cut with a knife. | Chritical angle 40½ | |||||
| Tolerates no heat. Softens at 150°C, melts at about 250°C. May burn. Surface structure is changed by heating, resulting in quicker decomposition of Amber. | No birefringence. | |||||
| Some Amber is dissolved by organic solvents. This especially is the case with Danish and Baltic Amber. | ||||||
| Amber
is more or less fossilized resin. Its found in many places
on the Earth. It may contain insects, but also
fragments of plants. Copal is a lesser hardened fossilized resin. |
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| Cutting | Polishing | |||||
| Lap | Powder | Speed | ||||
| Culet-angle 43° | Crown-angle 42° | Vax | Linde A | Normal to low | ||
| Fine Diamond cutting lap. | Tin/lead | Linde A | 35 rpm | |||
| Use a lot of water and low speed, or the lap will clutter up. | Lightside Acrylic/Lucite CD-Rom |
14.000 Diamond 50.000 Diamond CeriumOxide |
Low to very low | |||
| To be dopped with something without organic solvents - like white glue or Water Glass - that may be removed with water. | High speed may make Amber flow like plastic. | |||||
| Cutting
Amber is easy. Amber behaves much like plastic, it's light brittle,
and is quickly overcut. At to great pressure Amber will flow, and polishing may be difficult. Copal flows even more under pressure, hence it's not as easily faceted. |
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| Jón Olaf Svane | ||||||
Updated d. 19.6.2015