(under the class definition) Subject matter including a support for a crystal or gem for examination by visible light, a light source passing light through or reflecting light from the crystal or gem and usually structure to view, mark, or locate the light patterns correlated to some condition of the crystal or gem.
(1) Note. Included in this subclass are apparatus and method claims which include nominal cutting or etching structure or steps to prepare the crystal for examination in addition to the claimed test.
(2) Note. The optical testing of piezoelectric and semiconductor crystals are included in this subclass.
SEE OR SEARCH THIS CLASS, SUBCLASS:
36, for sample preparation wherein the novelty is in the preparation of the sample for an optical test and not provided for elsewhere.
72, for an optical test combined with another are device and not provided for elsewhere.
SEE OR SEARCH CLASS
29, Metal Working,
25.35, for piezoelectric device making methods, which include cutting and etching steps.
125, Stone Working,
12, and 13.01 for apparatus and methods for cutting crystals which include the step of first examining optically and marking the crystal for axis orientation. Also, see subclass 35 for work supports for cutting the crystal.
156, Adhesive Bonding and Miscellaneous Chemical Manufacture,
625+, for methods including a chemical etching step.
378, X-Ray or Gamma Ray Systems or Devices,
73+, for methods and apparatus for X-ray analysis of crystals which may include a support for the crystal.
