| 摘要 |
A dop stick with an oval cabachon adhesively mounted thereon for application to a grinding stone has two axes of rotation, one axis to determine the longitudinal curvature of the face of the cabachon, the other to determine the transverse curvature, and may be moved at random about the two axes of rotation simultaneously without departing from accurate positioning of the cabachon for correctly grinding the cabachon face.
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