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:
Dec. 23, 1980
Filed:
Sep. 14, 1979
Hisashi Machida, Otsu, JP;
Yoichiro Yoshihara, Otsu, JP;
Kyoto Ceramic Co., Ltd., Kyoto, JP;
Abstract
Disclosed is a synthetic single crystal for an alexandrite gem, which consists essentially of a synthetic chrysoberyl single crystal comprising aluminum oxide and beryllium oxide as the main components and chromium and vanadium as the coloring components, wherein vanadium is contained in an amount of about 0.00075 to about 2.95% by weight based on the crystal. This single crystal shows a green or bluish green color under natural light and the color is changed to red or reddish violet when the single crystal is exposed to tungsten light the single crystal of the present invention is comparable or superior to natural alexandrite produced in the Ural Mountain Region with respect to the hue and color change characteristics.