The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 24, 2001
Filed:
May. 12, 1999
Solomon Menashi, Newton, MA (US);
David Barrett, Grand Island, NY (US);
Wayne Duderwick, Williamsville, NY (US);
Randolph M. Bogdan, West Seneca, NY (US);
Ceres Corporation, Niagara Falls, NY (US);
Abstract
It has been learned that moissanite and other synthetic stones, including synthetic moissanite and synthetic diamond, are distinguishable from natural diamonds based on differing electrical conductivities. The present invention, therefore, provides an apparatus and method for determining a gem type based on its electrical conductivity. In particular, an electronic circuit including the gem under test as part of a circuit path is used to measure its electrical conductivity and, therefore, gem type. The onerous task of determining whether a gem is moissanite or synthetic diamond involves providing a high voltage across a gem surface greater than a breakdown voltage, typically greater than,volts, and measuring a minuscule current that flows through the gem. A first and second contact couple the high voltage to the gem under test, where a low impedance detection circuit is used to flag when the contacts are erroneously contacting each other during a measurement. Sampling techniques are employed to avoid false readings based on AC coupled noise and an optional conductive block with holes or cavities is used to retain loose gems during the testing process.