US3950596A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Altering the appearance of corundum crystals
Assignee: Astrid Corp Ltd
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Filing: 1974-05-08
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Granted: 1976-04-13
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Expires: 1994-05-08
Abstract
Abstract A corundum crystal whose surface is altered by contact with a powdered metal oxide colorant at an elevated temperature within the range of 1600 DEG C to a temperature below the fusion temperature of the said powder, said metal oxide colorant consisting essentially of an oxide of titanium and at least one metal oxide selected from the group consisting of iron, chromium, vanadium and nickel, said metal oxide colorant being sufficient to impart color to the surface of the crystal.
Inventors
- 👤 Ronald Ray Carr
- 👤 Stephen Dale Nisevich
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:26
CPC Classifications
C; C30; C30B; C30B29/00; C30B29/10; C30B29/16; C30B29/22; C30B29/26; C30B29/20; C30B31/00; C30B31/02
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
88 words
A corundum crystal initially having a non-uniform color appearance whose surface is altered by contact with a powdered metal oxide colorant at an elevated temperature within the range of 1600° C to a temperature below the fusion temperature of the said powder, said metal oxide colorant consisting essentially of an oxide of titanium and at least one metal oxide selected from the group consisting of iron, chromium, vanadium and nickel, said metal oxide colorant being sufficient to impart to the surface of the crystal a uniform color appearance.
Claim 2
Dependent Claim
88 words
A corundum crystal initially having a non-uniform color appearance whose surface is altered by contact with a powdered metal oxide colorant at an elevated temperature within the range of 1600° C to a temperature below the fusion temperature of the said powder, said metal oxide colorant consisting essentially of an oxide of titanium and at least one metal oxide selected from the group consisting of iron, chromium, vanadium and nickel, said metal oxide colorant being sufficient to impart to the surface of the crystal a uniform color appearance.
Claim 3
Dependent Claim
13 words
The corundum crystal of claim 1 wherein said crystal is an asteriated crystal.
Claim 4
Dependent Claim
18 words
The corundum crystal of claim 1 wherein at leaast one said metal oxide is an oxide of chromium.
Claim 5
Dependent Claim
18 words
The corundum crystal of claim 1 wherein at least one said metal oxide is an oxide of iron.
Claim 6
Dependent Claim
94 words
A corundum crystal initially having a first color appearance whose surface is altered by contact with a powdered metal oxide colorant at an elevated temperature within the range of 1600° C to a temperature below the fusion temperature of the said powder, said metal oxide colorant consisting essentially of an oxide of titanium and at least one metal oxide selected from the group consisting of iron, chromium, vanadium and nickel, said metal oxide colorant being sufficient to impart to the surface of the crystal a second color appearance different from the first color appearance.
Claim 7
Dependent Claim
94 words
A corundum crystal initially having a first color appearance whose surface is altered by contact with a powdered metal oxide colorant at an elevated temperature within the range of 1600° C to a temperature below the fusion temperature of the said powder, said metal oxide colorant consisting essentially of an oxide of titanium and at least one metal oxide selected from the group consisting of iron, chromium, vanadium and nickel, said metal oxide colorant being sufficient to impart to the surface of the crystal a second color appearance different from the first color appearance.
Claim 8
Dependent Claim
13 words
The corundum crystal of claim 5 wherein said crystal is an asteriated crystal.
Claim 9
Dependent Claim
18 words
The corundum crystal of claim 5 wherein at least one said metal oxide is an oxide of chromium.
Claim 10
Dependent Claim
18 words
The corundum crystal of claim 5 wherein at least one said metal oxide is an oxide of iron.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-04-13 | 1979-10-13 | 1980-04-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-04-13 | 1983-10-13 | 1984-04-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-04-13 | 1987-10-13 | 1988-04-13 | $7700.00 | Window Closed / Lapsed |