Faceted gem cut from shallow gemstone material
Patent 4708001 Issued on November 24, 1987. Estimated Expiration Date: 
September 4, 2005. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
September 4, 2005. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesInventorApplicationNo. 06/772434 filed on 09/04/1985US Classes:63/32, GEMD11/90FacetedExaminersPrimary: Johnson, Richard J.International ClassA44C 17/00 (20060101)AbstractA faceted gem having a polished cone-shaped depression cut into the pavillion, said cone being concentric with the vertical axis of the gemstone, and having an included angle at the cone apex of about 90°, and a base diameter equal to about 50% of the girdle diameter. The thus-described polished cone surface reflects light entering the crown, providing a brilliance about equal to that of a correctly-cut gem having full depth of the pavillion. At the same time, the polished internal cone configuration of the pavillion permits a shallow stone to be cut to a maximum girdle diameter, such that the yield in stone size is increased by as much as 50% or more, as compared with the yield obtainable by cutting the pavillion in the conventional manner with correct main angles. | |
