US2998365A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Treatment of diamonds
Assignee: Industrial Distributors 1946 Ltd
•
Filing: 1955-04-11
•
Granted: 1961-08-29
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Expires: 1975-04-11
Abstract
No abstract record available.
Inventors
- 👤 Jan F H Custers
- 👤 Dyer Henry Brooke
- 👤 Ditchburn Robert William
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 17:26
CPC Classifications
A; A44; A44C; A44C17/00; A44C17/04; C; C01; C01B; C01B32/00; C01B32/25; C01B32/28
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
38 words
A METHOD OF IMPROVING THE COLOR OF A DIAMOND BY INCREASING ITS LIGHT ABSORPTION TOWARDS THE RED END OF THE VISIBLE SPECTRUM CONSISTING IN EXPOSING THE DIAMOND TO GAMMA RADIATION HAVING AN ENERGY BETWEEN 0.5 AND 1.3 M.E.V.
Claim 2
Independent Claim
38 words
A METHOD OF IMPROVING THE COLOR OF A DIAMOND BY INCREASING ITS LIGHT ABSORPTION TOWARDS THE RED END OF THE VISIBLE SPECTRUM CONSISTING IN EXPOSING THE DIAMOND TO GAMMA RADIATION HAVING AN ENERGY BETWEEN 0.5 AND 1.3 M.E.V.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-08-28 | 1965-02-27 | 1965-08-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-08-28 | 1969-02-27 | 1969-08-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-08-28 | 1973-02-27 | 1973-08-29 | $7700.00 | Window Closed / Lapsed |