Lap for the polishing of gemstones

摘要

There is provided a scaife for the polishing of gemstones wherein the abrasive material is embedded in a matrix of a material maintained in the solid state, which material has a high enthalpy of phase transition from solid to liquid. Suitable materials are frozen water, frozen water/organic liquid mixtures such as water/alkanol mixtures and suitable metals or metal alloys. There is also provided a process for the polishing of gemstones which comprises establishing a layer of abrasive embedded in a suitable solid matrix in or on the surface of a rotatory plate and polishing the gemstones, overheating being prevented by the high enthalpy of solid/liquid transition of the said matrix.