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| Fig 161 a The Potteratmaster allows a clear view of the girdle zone | Fig 161 b The Potteratmaster can also be used in combination with a microscope |
Instead of the usual stone holder a Potteratmaster is used which simplified considerably the technique of microscopy. With the help of a Potteratmaster the stone can be observed by rotating the vertical axis, and table, crown, girdle, pavilion and culet of a brilliant without resetting the stone. The stone holder can be used with a loupe as well as in conjunction with a microscope. The conventional tongs force the examiner to put down the stone several times and then to take it up again in order to be able to view it from another direction.
It is also a disadvantage of the traditional stone holders that the stone will jump out of the tongs when surface dust is to be removed, and that the optical field' can be influenced by mirroring the tongs and the teeth of the tweezers.
| Sortoscope | Instructions for Practical Clarity Grading |