Memorial diamonds are produced using hair or ashes, often with other carbon ("lab carbon") added. In case of hair, it is subjected to heat treatment to extract carbon. Some laboratories also analyze the content of hair. A hair analysis report then serves as a client assurance. The process of unique identification of a diamond and a person based on the hair composition is described in the diamond patent RU2282584 Carbon can be obtained from cremated human or animal remains in a particulate or gaseous form. The carbon is then filtered using a conventional filtering technique. The carbon and other elements are then purified and graphitized, for example by a halogen purification technique. The percentage of carbon used that is extracted from the provided material varies by service provider, with some memorial diamonds containing as little as 3% carbon from the provided material, while at least one producer uses only carbon from the provided material. Some memorial diamonds are graded by
gemological laboratories, such as
Gemological Institute of America (US) or
Birmingham Assay Office (United Kingdom). == See also ==