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1. (WO1998052774) DIAMOND MARKING

Pub. No.:    WO/1998/052774    International Application No.:    PCT/GB1998/001497
Publication Date: Fri Nov 27 00:59:59 CET 1998 International Filing Date: Sat May 23 01:59:59 CEST 1998
IPC: B44B 7/00
Applicants: GERSAN ESTABLISHMENT
SMITH, James, Gordon, Charters
STEWART, Andrew, David, Garry
Inventors: SMITH, James, Gordon, Charters
STEWART, Andrew, David, Garry
Title: DIAMOND MARKING
Abstract:
An information mark invisible to the naked eye is applied to the polished facet of a diamond gemstone by coating the diamond gemstone surface with an electrically conductive layer so as to prevent the diamond becoming charged, forming the mark with a focused ion beam, and cleaning the diamond surface with a powerful oxidizing agent to reveal a mark having an appropriate depth, which does not detrimentally affect the clarity or colour grade of the diamond.