IL41125A - A process for altering the appearance characteristics of corundum crystals and product obtained thereby - Google Patents

A process for altering the appearance characteristics of corundum crystals and product obtained thereby

Info

Publication number
IL41125A
IL41125A IL41125A IL4112572A IL41125A IL 41125 A IL41125 A IL 41125A IL 41125 A IL41125 A IL 41125A IL 4112572 A IL4112572 A IL 4112572A IL 41125 A IL41125 A IL 41125A
Authority
IL
Israel
Prior art keywords
crystal
powder
oxide
appearance characteristics
appearance
Prior art date
Application number
IL41125A
Original Assignee
Astrid Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Astrid Corp filed Critical Astrid Corp
Publication of IL41125A publication Critical patent/IL41125A/en

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C30—CRYSTAL GROWTH
    • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
    • C30B29/00—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape
    • C30B29/10—Inorganic compounds or compositions
    • C30B29/16—Oxides
    • C30B29/22—Complex oxides
    • C30B29/26—Complex oxides with formula BMe2O4, wherein B is Mg, Ni, Co, Al, Zn, or Cd and Me is Fe, Ga, Sc, Cr, Co, or Al
    • C—CHEMISTRY; METALLURGY
    • C30—CRYSTAL GROWTH
    • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
    • C30B29/00—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape
    • C30B29/10—Inorganic compounds or compositions
    • C30B29/16—Oxides
    • C30B29/20—Aluminium oxides
    • C—CHEMISTRY; METALLURGY
    • C30—CRYSTAL GROWTH
    • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
    • C30B31/00—Diffusion or doping processes for single crystals or homogeneous polycrystalline material with defined structure; Apparatus therefor
    • C30B31/02—Diffusion or doping processes for single crystals or homogeneous polycrystalline material with defined structure; Apparatus therefor by contacting with diffusion materials in the solid state

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Crystals, And After-Treatments Of Crystals (AREA)
  • Pigments, Carbon Blacks, Or Wood Stains (AREA)
  • Inorganic Compounds Of Heavy Metals (AREA)

Claims (13)

WHAT IS CLAIMED IS:
1. A process for altering appearance characteristics of corundum crystal which comprises embedding an asteriated corundum crystal having undesired appearance characteristics in a powder containing 1% to 30% by weight titanium oxide, up to 207o by weight of a metal oxide corund colorant, the remainder alumina, and heating such crystal in contact with said powder at an elevated temperature belo the fusion temperatures of said powder and said crystal for a time sufficient to impart to the surface portions of said crystal desired appearance characteristics effective to mas said undesired appearance characteristics.
2. . The process of claim 1 wherein said metal oxide colorant is at least one oxide selected from the group consisting of oxide of iron, chromium, nickel and vanadium.
3. . The process of claim 2 wherein said process is carried out at a temperature within the range of from about 1600° to about 1850°C.
4. The process of claim 3 wherein said process is carried out for a period of from about 2 to about 200 hours .
5. The process of claim 3 wherein said process is carried out in an oxidizing atmosphere.
6. The process of claim 3 wherein said process is carried out in a reducing atmosphere.
7. The process of claim 6 wherein said powder contains an oxide of titanium and an oxide of iron.
8. The process of claim 7 wherein the powder contains from about 0.1 to about 0.5 weight per cent iron oxide, and from about 12 to about 18 weight per cent titanium oxide.
9. Process for producing a corundum cabochon free of visual color defects from a crystal having undesir appearance characteristics which process comprises embeddi such crystal in a powder containing a colorant metal oxide, titanium dioxide and alumina, the titanium oxide content being about 1% to 30%, the colorant not exceeding 207o, the remainder alumina; heating such crystal in contact with said powder at an elevated temperature below the fusion temperature of said powder for 2 to 200 hours to impart to surface portions of said crystal desired appearance characteristics; removing said crystal from said powder and polishing said crystal.
10. A process as defined in claim 9 including the further step of heating said crystal to an asteriatin ° ° 8820-1
11. A cabochon-cut asteriated corundum crystal having a core portion exhibiting appearance defects and a surface skin free of such appearance defects said skin being of such thickness as to effectively mask such core appearance defects and to impart to such crystal defect-free appearance.
12. A crystal as defined by claim 11 in which the thickness of said surface skin is 0.001 to 0.020 inch.
13. A crystal as defined by claim 11 in which said surface skin extends at least over the entire crown of said cabochon-cut crystal.
IL41125A 1971-12-20 1972-12-19 A process for altering the appearance characteristics of corundum crystals and product obtained thereby IL41125A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US21014071A 1971-12-20 1971-12-20
US312132A US3897529A (en) 1971-12-20 1972-12-04 Altering the appearance of corundum crystals

Publications (1)

Publication Number Publication Date
IL41125A true IL41125A (en) 1976-02-29

Family

ID=26904856

Family Applications (1)

Application Number Title Priority Date Filing Date
IL41125A IL41125A (en) 1971-12-20 1972-12-19 A process for altering the appearance characteristics of corundum crystals and product obtained thereby

Country Status (9)

Country Link
US (1) US3897529A (en)
AT (1) AT330722B (en)
BE (1) BE793007A (en)
CA (1) CA978836A (en)
CH (1) CH554811A (en)
DE (1) DE2262104A1 (en)
FR (1) FR2164690B1 (en)
GB (1) GB1408648A (en)
IL (1) IL41125A (en)

Families Citing this family (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
IT1168707B (en) * 1983-08-03 1987-05-20 Giovanni Colliva EQUIPMENT FOR CUTTING GEMS WITH SPHERICAL FACETS AND GEMS SO OBTAINED
IL69576A (en) * 1982-09-16 1986-08-31 Colliva Giovanni Apparatus for the cutting of spherical-faceted gems and gems thus obtained
US5126094A (en) * 1989-03-02 1992-06-30 Farzin Nia Farrokh Heat treatment of an orthodontic bracket
DE4201490A1 (en) * 1992-01-21 1993-07-22 Otto Feuerfest Gmbh FIRE-RESISTANT MATERIAL FOR ELECTROLYSIS OVENS, METHOD FOR THE PRODUCTION AND USE OF THE FIRE-RESISTANT MATERIAL
US5762896A (en) * 1995-08-31 1998-06-09 C3, Inc. Silicon carbide gemstones
US5664440A (en) * 1996-06-05 1997-09-09 Roemer; Thomas Bruce Enhanced diamond ring
US6635309B2 (en) * 2001-03-12 2003-10-21 Richard D. Pollak Process for the color enhancement of gemstones
US6872422B2 (en) 2001-07-09 2005-03-29 Samir Gupta Process for imparting and enhancement of colours in gemstone minerals and gemstone minerals obtained thereby
US7526928B1 (en) 2002-11-04 2009-05-05 Azotic Coating Technology, Inc. Multi-color gemstones and gemstone coating deposition technology
US6997014B2 (en) * 2002-11-04 2006-02-14 Azotic Coating Technology, Inc. Coatings for gemstones and other decorative objects
CN110241458A (en) * 2019-05-24 2019-09-17 淅川正弘单晶刚玉厂 The production method of canescence single alundum

Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US988230A (en) * 1910-05-10 1911-03-28 Heller & Son L Process of producing synthetic sapphires.
US1814219A (en) * 1926-05-17 1931-07-14 Ig Farbenindustrie Ag Process of improving certain physical properties of synthetic precious stones
US1775867A (en) * 1928-01-19 1930-09-16 Swiss Jewel Co S A Synthetic oriental emerald or emerald-green sapphire
US2448511A (en) * 1943-10-01 1948-09-07 Linde Air Prod Co Glossing corundum and spinel
US2488507A (en) * 1947-08-27 1949-11-15 Linde Air Prod Co Synthetic star rubies and star sapphires, and process for producing same
US2690062A (en) * 1949-12-21 1954-09-28 Union Carbide & Carbon Corp Synthetic corundum crystals and process for making same
US2690630A (en) * 1951-12-28 1954-10-05 Union Carbide & Carbon Corp Producing asteriated corundum crystals
FR1067037A (en) * 1951-12-28 1954-06-11 Union Carbide & Carbon Corp Process for manufacturing corundum crystals with a star structure
FR1119461A (en) * 1954-02-19 1956-06-20 Degussa Synthetic jewelry and their manufacturing processes
BE635034A (en) * 1962-08-10
US3539379A (en) * 1968-05-02 1970-11-10 Liner Technology Inc Process for coating gem stones
US3713877A (en) * 1969-02-10 1973-01-30 H Kirchner Method of strengthening ceramic bodies and strengthened ceramic bodies produced thereby

Also Published As

Publication number Publication date
ATA1084872A (en) 1975-10-15
BE793007A (en) 1973-06-19
FR2164690B1 (en) 1976-10-29
GB1408648A (en) 1975-10-01
FR2164690A1 (en) 1973-08-03
AT330722B (en) 1976-07-12
CH554811A (en) 1974-10-15
CA978836A (en) 1975-12-02
US3897529A (en) 1975-07-29
DE2262104A1 (en) 1973-07-19

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