Device for judging brilliancy of precious stones such as diamonds or the like
US4647194A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 28, 1984 |
| Grant date | Mar 3, 1987 |
| Priority date | — |
| Expiry date | Jun 28, 2004 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/8803
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A device for judging precious stones such as diamonds with ease, especially enables judgment of quality of cut, clarity or existence of imperfections and color grade of diamonds without requiring expert skill or experience. The device body (1) is provided with a window (3) at its upper part and light source (2) at its lower part. A plate (4) for supporting precious stones such as diamonds, is slidably inserted and carried between the window (3) and the light source (2). A base plate (14) which is slidably secured, is also provided to the device body (1), and a magnifying glass (12) for presenting precious stones in enlargement through the window (3), is fixed to the base plate (14). On the object lens side of the magnifying glass (12) is mounted a disc (17) having a small hole (18). The exterior of the disc (17) is colored in red or silver.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.