Heat-resistant synthetic jewelry material

Abstract

A heat-resistant synthetic jewelry material having a transparent, semitransparent or nontransparent composite nanocrystalline material on the basis of nanosized oxide and silicate crystalline phases. The material includes at least one of the following crystalline phases: spinel, quartz-like phases, sapphirine, enstatite, petalite-like phase, cordierite, willemite, zirconium, rutile, zirconium titanate, zirconium dioxide with a content of ions of transition elements, rare-earth elements and precious metals of from 0.001 to 4 mol %. One of the crystalline phases is additionally quartz-like solid solutions of lithium magnesium zinc aluminosilicates with a virgilite or keatite structure. The composition is selected from the following components,s SiO.sub.2, Al.sub.2O.sub.3, MgO, ZnO, Li.sub.2O, PbO, ZrO.sub.2, TiO.sub.2, NiO, CoO, CuO, Cr.sub.2O.sub.3, Bi.sub.2O.sub.3, Fe.sub.2O.sub.3, MnO.sub.2, CeO.sub.2, Nd.sub.2O.sub.3, Er.sub.2O.sub.3, Pr.sub.2O.sub.3 and Au.

Claims

1. A heat-resistant synthetic jewelry material comprising: a composite nanocrystalline material having nanosized oxide and silicate crystalline phases, the composite nanocrystalline material comprising: at least one crystalline phase selected from the group consisting of: spinel, quartz-like phases, sapphirine, enstatite, petalite-like phases, cordierite, willemite, zircon, magnesium aluminotitanates, rutile, zirconium titanate, and zirconium dioxide, and having a content of ions of transition elements, rare-earth elements and precious metals of from 0.001 to 4 mol %, at least one crystalline phase comprising solid solutions of lithium magnesium zinc aluminosilicates with a virgilite or keatite structure, wherein the composite nanocrystalline material comprises, in mol %: SiO.sub.2—45-72; Al.sub.2O.sub.3—15-30; MgO—0.1-23.9; ZnO—0.1-29; Li.sub.2O—1-18; PbO—0.1-7.0; ZrO.sub.2—0.1-10; TiO.sub.2—0.1-15; NiO—0.001-4.0; CoO—0.001-3.0; CuO—0.001-4.0; Cr.sub.2O.sub.3—0.001-1.0; Bi.sub.2O.sub.3—0.001-3.0; Fe.sub.2O.sub.3—0.001-3.0; MnO.sub.2—0.001-3.0; CeO.sub.2—0.001-3.0; Nd.sub.2O.sub.3—0.001-3.0; Er.sub.2O.sub.3—0.001-3.0; Pr.sub.2O.sub.3—0.001-3.0; Au—0.001-1.0.

2. The heat-resistant synthetic jewelry material of claim 1, wherein the composite nanocrystalline material is transparent, translucent, or opaque.

3. A heat-resistant synthetic jewelry material comprising: a composite nanocrystalline material having nanosized oxide and silicate crystalline phases, the composite nanocrystalline material comprising: at least one crystalline phase selected from the group consisting of: spinel, quartz-like phases, sapphirine, enstatite, petalite-like phase, cordierite, willemite, zircon, magnesium aluminotitanates, rutile, zirconium titanate, and zirconium dioxide; and at least another crystalline phase comprising solid solutions of lithium magnesium zinc aluminosilicates with virgilite or keatite structure, wherein the composite nanocrystalline material comprises the following in mol %: SiO.sub.2—45-72; Al.sub.2O.sub.3—15-30; MgO—0.1-23.9; ZnO-0.1-29; Li.sub.2O—1-18; PbO—0.1-7.0; ZrO.sub.2—0.1-10; TiO.sub.2—0.1-15; NiO—0.001-4.0; CoO—0.001-3.0; CuO—0.001-4.0; Cr.sub.2O.sub.3—0.001-1.0; Bi.sub.2O.sub.3—0.001-3.0; Fe.sub.2O.sub.3—0.001-3.0; MnO.sub.2—0.001-3.0; CeO.sub.2—0.001-3.0; Nd.sub.2O.sub.3—0.001-3.0; Er.sub.2O.sub.3—0.001-3.0; Pr.sub.2O.sub.3—0.001-3.0; Au—0.001-1.0.

4. The heat-resistant synthetic jewelry material of claim 3, wherein the composite nanocrystalline material is transparent, translucent, or opaque.

5. The heat-resistant synthetic jewelry material of claim 3, wherein the at least one crystalline phase comprises ions selected from the group consisting of transition elements, rare-earth elements, precious metals and compositions thereof.

6. The heat-resistant synthetic jewelry material of claim 5, wherein the ions comprise 0.001 to 4 mol % of the composite nanocrystalline material.

7. A heat-resistant synthetic jewelry material composition comprising: a composite nanocrystalline material, wherein the composite nanocrystalline material comprises: 45-72 mole percent SiO.sub.2; 0.1-23.9 mole percent Al.sub.2O.sub.3; 0.1-23.9 mole percent MgO; 0.1-29 mole percent ZnO; 1.0-18.0 mole percent Li.sub.2O; 0.1-7.0 mole percent PbO; 0.1-10.0 mole percent ZrO.sub.2; 0.1-15.0 mole percent TiO.sub.2; 0.001-4.0 mole percent NiO; 0.001-3.0 mole percent CoO; 0.001-1.0 mole percent CuO; 0.001-3.0 mole percent Cr.sub.2O.sub.3; 0.001-3.0 mole percent Bi.sub.2O.sub.3; 0.001-3.0 mole percent Fe.sub.2O.sub.3; 0.001-3.0 mole percent MnO.sub.2; 0.001-3.0 mole percent CeO.sub.2; 0.001-3.0 mole percent Nd.sub.2O.sub.3; 0.001-3.0 mole percent Er.sub.2O.sub.3; 0.001-3.00 mole percent Pr.sub.2O.sub.3; and 0.001-1.0 mole percent Au.

8. The heat-resistant synthetic jewelry material composition of claim 7, wherein the material is transparent, translucent or opaque.

9. The heat-resistant synthetic jewelry material composition of claim 7, wherein the composite nanocrystalline material has nanosized oxide and silicate crystalline phases.

10. The heat-resistant synthetic jewelry material composition of claim 7, wherein composite nanocrystalline material comprises at least one crystalline phase selected from the group consisting of: spinel, quartz phases, sapphirine, enstatite, petalite phases, cordierite, willemite, zircon, magnesium aluminotitanates, rutile, zirconium titanate, and zirconium dioxide.

Description

The Best Examples

(1) TABLE-US-00002 TABLE 2 Sample No 1 2 3 Component Concentration (mol %) SiO.sub.2 45 54.9 72 Al.sub.2O.sub.3 30 15 16 MgO 23.9 0.1 4 ZnO 0.1 29 4 Li.sub.2O 1 1 4 ZrO.sub.2 0.1 10 6 TiO.sub.2 15 3 0.1 PbO 0.1 2 7.0 NiO 4 1.0 0.001 CoO 0.001 0.005 3.000 CuO 0.001 0.001 0.001 Cr.sub.2O.sub.3 0.001 0.001 0.001 Bi.sub.2O.sub.3 0.001 0.001 0.001 Fe.sub.2O.sub.3 0.001 0.001 0.001 MnO.sub.2 0.001 0.001 0.001 CeO.sub.2 0.001 0.001 0.001 Nd.sub.2O.sub.3 0.001 0.001 0.001 Er.sub.2O.sub.3 0.001 0.001 0.001 Pr.sub.2O.sub.3 0.001 0.001 0.001 Au 0.001 0.001 0.001 Heat-treatment conditions 1 stage 660° C., 24 h 800° C., 4 h  770° C., 12 h 2 stage 900° C., 24 h 1000° C., 12 h 1200° C., 1 h Colour Green, Green, Green, transparent opaque opaque  Thermal 15.0 19.0 22.0 expansion coefficient (×10.sup.−7/° C.) Glass melting 1540 1540 1550 temperature, ° C. Crystalline Solid solution of Solid solution of Solid solution of phases lithium-magnesium- lithium-magnesium- lithium-magnesium- zinc-aluminosilicate zinc-aluminosilicate zinc-aluminosilicate with virgilite (β- with β-spodumene with β-spodumene quartz) structure (keatite) structure (keatite) structure Spinel Spinel Spinel Magnesium Zircon Cordierite aluminotitanates Petalite-like phase Rutile Zirconium titanate Zirconium dioxide Zirconium dioxide Sample No 4 5 6 Component Concentration (mol %) SiO.sub.2 45 54.9 70 Al.sub.2O.sub.3 30 15 18 MgO 12.9 0.1 6 ZnO 0.1 12 3 Li.sub.2O 12 18 3 ZrO.sub.2 0.1 10 5 TiO.sub.2 15 0.1 5 PbO 0.1 2 7.0 NiO 0.001 0.001 0.001 CoO 0.001 0.001 0.001 CuO 4.000 0.050 0.000 Cr.sub.2O.sub.3 0.001 0.001 0.001 Bi.sub.2O.sub.3 0.001 0.001 3.000 Fe.sub.2O.sub.3 0.001 0.001 0.001 MnO.sub.2 0.001 0.001 0.001 CeO.sub.2 0.001 0.001 0.001 Nd.sub.2O.sub.3 0.001 0.001 0.001 Er.sub.2O.sub.3 0.001 0.001 0.001 Pr.sub.2O.sub.3 0.001 3.000 0.001 Au 0.001 0.001 0.001 Heat-treatment conditions 1 stage 720° C., 6 h 700° C., 12 h  750° C., 1 h 2 stage 1050° C., 24 h 850° C., 12 h 1200° C., 1 h Colour Brown, Bluish-green, Deep-brown, opaque transparent opaque Thermal 18.0 5.0 12.0 expansion coefficient (×10.sup.−7/° C.) Glass melting 1520 1520 1550 temperature, ° C. Crystalline Solid solution of Solid solution of Solid solution of phases lithium-magnesium- lithium-magnesium- lithium-magnesium- zinc-aluminosilicate zinc-aluminosilicate zinc-aluminosilicate with β-spodumene with virgilite (β- with β-spodumene (keatite) structure quartz) structure (keatite) structure Sapphirine Spinel Cordierite Enstatite Zirconium titanate Zirconium titanate Magnesium Zirconium dioxide aluminotitanates Sample No 7 8 9 Component Concentration (mol %) SiO.sub.2 45 54.9 70 Al.sub.2O.sub.3 30 15 18 MgO 14.9 0.1 6 ZnO 0.1 20 2 Li.sub.2O 10 10 4 ZrO.sub.2 0.1 10 5 TiO.sub.2 15 3 0.1 PbO 0.1 2 7.0 NiO 0.001 0.001 0.001 CoO 0.001 0.001 0.001 CuO 0.001 0.001 0.001 Cr.sub.2O.sub.3 1.000 0.001 0.001 Bi.sub.2O.sub.3 0.001 0.001 0.001 Fe.sub.2O.sub.3 0.001 3.000 0.001 MnO.sub.2 0.001 0.001 0.001 CeO.sub.2 0.001 0.100 3.000 Nd.sub.2O.sub.3 0.001 0.001 0.001 Er.sub.2O.sub.3 0.001 0.001 0.001 Pr.sub.2O.sub.3 0.001 0.001 0.001 Au 0.001 0.001 0.001 Heat-treatment conditions 1 stage 680° C., 24 h  800° C., 12 h  780° C., 1 h 2 stage 800° C., 24 h 1100° C., 12 h 1200° C., 1 h Colour Smoky, Light-brown, Brown, transparent opaque opaque Thermal 3.0 10.0 12.0 expansion coefficient (×10.sup.−7/° C.) Glass melting 1530 1520 1545 temperature, ° C. Crystalline Solid solution of Solid solution of Solid solution of phases lithium-magnesium- lithium-magnesium- lithium-magnesium- zinc-aluminosilicate zinc-aluminosilicate zinc-aluminosilicate with virgilite (β- with virgilite (β- with virgilite (β- quartz) structure quartz) structure quartz) structure Spinel Willemite Cordierite Magnesium Spinel Zirconium dioxide aluminotitanates Zircon Zirconium titanate Zirconium dioxide Sample No 7 8 9 Component Concentration (mol %) SiO.sub.2 45 54.9 70 Al.sub.2O.sub.3 30 15 18 MgO 10.0 0.1 6 ZnO 0.1 16 3 Li.sub.2O 14.9 14 3 ZrO.sub.2 0.1 10 5 TiO.sub.2 15 3 0.1 PbO 0.1 2 7.0 NiO 0.001 1.0 0.001 CoO 0.001 0.001 0.001 CuO 0.001 0.001 0.001 Cr.sub.2O.sub.3 0.001 0.001 0.001 Bi.sub.2O.sub.3 0.001 0.001 0.001 Fe.sub.2O.sub.3 0.001 0.001 0.001 MnO.sub.2 3.000 0.003 0.001 CeO.sub.2 0.000 0.000 0.000 Nd.sub.2O.sub.3 0.001 0.001 0.001 Er.sub.2O.sub.3 0.001 0.500 3.000 Pr.sub.2O.sub.3 0.001 0.001 0.001 Au 0.001 0.001 0.001 Heat-treatment conditions 1 stage 680° C., 24 h 780° C., 12 h  800° C., 1 h 2 stage 820° C., 24 h 900° C., 12 h 1200° C., 1 h Colour Light-brown, Rosy, Rosy, transparent transparent opaque Thermal 2.0 5.0 21.0 expansion coefficient (×10.sup.−7/° C.) Glass melting 1520 1520 1550 temperature, ° C. Crystalline Solid solution of Solid solution of Solid solution of phases lithium-magnesium- lithium-magnesium- lithium-magnesium- zinc-aluminosilicate zinc-aluminosilicate zinc-aluminosilicate with virgilite (β- with virgilite (β- with β-spodumene quartz) structure quartz) structure (keatite) structure Spinel Spinel Cordierite Magnesium Zirconium titanate Zirconium dioxide aluminotitanates Zirconium dioxide Sample No 4 5 6 Component Concentration (mol %) SiO.sub.2 45 54.9 70 Al.sub.2O.sub.3 30 15 18 MgO 12.9 0.1 6 ZnO 0.1 12 3 Li.sub.2O 12 18 3 ZrO.sub.2 0.1 10 5 TiO.sub.2 15 0.1 5 PbO 0.1 2 7.0 NiO 0.001 0.001 0.001 CoO 0.001 0.001 0.001 CuO 0.001 0.001 0.001 Cr.sub.2O.sub.3 0.001 0.001 0.001 Bi.sub.2O.sub.3 0.001 0.001 0.001 Fe.sub.2O.sub.3 0.001 0.001 0.001 MnO.sub.2 0.001 0.001 0.001 CeO.sub.2 0.001 0.001 0.001 Nd.sub.2O.sub.3 0.001 0.001 3.000 Er.sub.2O.sub.3 0.001 0.001 0.001 Pr.sub.2O.sub.3 0.001 0.001 0.001 Au 0.003 1.000 0.001 Heat-treatment conditions 1 stage 720° C., 6 h 700° C., 12 h  750° C., 1 h 2 stage 1050° C., 24 h 850° C., 12 h 1200° C., 1 h Colour Purple, Red, Lilac, opaque transparent opaque Thermal 18.0 3.0 12.0 expansion coefficient (×10.sup.−7/° C.) Glass melting 1520 1520 1550 temperature, ° C. Crystalline Solid solution of Solid solution of Solid solution of phases lithium-magnesium- lithium-magnesium- lithium-magnesium- zinc-aluminosilicate zinc-aluminosilicate zinc-aluminosilicate with β-spodumene with virgilite (β- with β-spodumene (keatite) structure quartz) structure (keatite) structure Sapphirine Spinel Cordierite Enstatite Zirconium titanate Zirconium dioxide Magnesium Zirconium dioxide aluminotitanates

INDUSTRIAL APPLICABILITY

(2) Introduction of SiO.sub.2 in an amount less than suggested does not lead to the formation of transparent material during glass melting, and the introduction of SiO.sub.2 in an amount greater than suggested increases the melting temperature of the melt to temperatures exceeding 1600° C., thus no standard glass-making equipment can be used for glass melting. It impedes obtaining the pure glass melt. Introduction of Li.sub.2O in an amount smaller and larger than the concentration range claimed prevents the obtaining of solid solutions of lithium-magnesium-zinc-aluminosilicate with virgilite (β-quartz) or keatite structure, lowering the CTE of the material obtained. Introduction of Al.sub.2O.sub.3, MgO, ZnO and Li.sub.2O in an amount smaller and larger than the concentration range claimed, prevents the obtaining of transparent initial glass. Introduction of PbO in amounts less than suggested, does not lead to increasing refractive index of the material. Introduction of PbO in an amount larger than the concentration range claimed prevents the obtaining of transparent initial glass. Introduction of TiO.sub.2 and ZrO.sub.2 in an amount less than claimed prevents obtaining the solid monolithic material after the secondary heat-treatment. Introduction of TiO.sub.2 and ZrO.sub.2 in an amount greater than claimed leads to crystallization of the glass melt during casting. Introduction of the colouring agents NiO, CoO, CuO, Cr.sub.2O.sub.3, Bi.sub.2O.sub.3, Fe.sub.2O.sub.3, MnO.sub.2, CeO.sub.2, Nd.sub.2O.sub.3, Er.sub.2O.sub.3, Pr.sub.2O.sub.3 and Au in an amount less than claimed does not lead to material colouration. Introduction of NiO, CoO, CuO, Cr.sub.2O.sub.3, Bi.sub.2O.sub.3, Fe.sub.2O.sub.3, MnO.sub.2, CeO.sub.2, Nd.sub.2O.sub.3, Er.sub.2O.sub.3, Pr.sub.2O.sub.3 and Au in an amount greater than claimed leads to crystallization of the glass melt during casting.

(3) Additional heat-treatment of the glass at the first stage at below 660° C. does not lead to liquid phase-separation and crystallization of titanium- and zirconium-containing phases, ensuring nanoscale crystallization of the initial glass. Additional heat-treatment of the glass at the first stage at above 800° C. leads to crystallization of large-size silicate crystals that damages the integrity of samples. The duration of the heat-treatment at the first stage which is less than 1 hour does not result in the phase separation of the initial glass, which damages the integrity of the samples after the heat treatment at the second stage. The duration of the heat treatment on the first stage which is more than 24 hours results in crystallization of undesired crystalline phases and therefore does not result in the desired colouration.

(4) Heat treatment of the samples in the second stage at a temperature below 780° C. does not lead to crystallization of the desired phases, and therefore, does not result in the desired colours. Heat treatment of the samples in the second stage at a temperature above 1200° C. leads to melting of the material. The duration of the heat treatment in the second step which is less than 1 hour is unsufficient for crystallization. The duration of the second stage heat treatment which is more than 24 hours results in the destruction of crystals and colour loss.

(5) The initial glass was heat-treated according to the schedules listed in Table 2. The characteristic of the crystalline phases was determined using X-ray diffraction analysis. The coefficient of thermal expansion and thermal shock resistance were measured as well. In each experiment, the initial glass was heated to a first temperature plateau at a rate of 300° C./hr, then was hold for a time sufficient to develop liquid phase separation, then the temperature was raised to a second plateau at a rate of 300° C./hour, and the material was hold for a time sufficient for crystallization of nanosized crystals of solid solution of lithium-magnesium-zinc-aluminosilicates with virgilite (β-quartz) structure or solid solution of lithium-magnesium-zinc-aluminosilicates with β-spodumene (keatite) structure and/or spinel, and/or quartz-like solid solutions, and/or sapphirine, and/or enstatite, and/or petalite, and/or cordierite, and/or willemite, and/or magnesium aluminotitanates, and/or zircon, and/or rutile, and/or zirconium titanate, and/or zirconium dioxide. The sample thus obtained was cooled to room temperature with the furnace.

(6) Proposed material obtained by this method possesses uniform colour, optical characteristics similar to the characteristics of the main natural coloured minerals and manufacturable. A very important advantage of the material is its low coefficient of thermal expansion, hardness, chemical resistance and colour stability to thermal shock, which allows, in particular, accelerated mode of grinding and polishing as well as permits using the method of “casting with precious stones”, as not only the faceted samples do not crack in contact with the of silver or gold melt, but they're also able to retain their colour.