INVENTION
Russian Federation Patent RU2119977
METHOD OF TREATMENT GROUPS ornamental stones of chalcedony

METHOD OF TREATMENT GROUPS ornamental stones of chalcedony. ORNAMENTS. JEWELRY. GOLD. PLATINUM. DIAMOND. Diamonds. KNOW-HOW. TREATMENT. Cut. GEM. INTRODUCTION. PATENT. TECHNOLOGIES.

INVENTION. METHOD OF TREATMENT GROUPS ornamental stones of chalcedony. Russian Federation Patent RU2119977

Name of applicant: Geological Faculty of Moscow State University Lomonosov
Name of the inventor: Dimitrova OV
The name of the patentee: Geological Faculty of Moscow State University Lomonosov
Address for correspondence:
Starting date of the patent: 1996.05.07

Use: in the manufacture of jewelry to improve their artistic and decorative properties. Summary of the invention consists in the fact that the pre-polished samples were placed in a solution of 5-35% alkali solution (LiOH, NaOH, KOH) and their processing is performed under hydrothermal conditions at T - 50-300 o C and F - 50-500 atm for 5-25 hours. A group of ornamental stones of chalcedony having enhanced decorative effect by increasing the brightness of the stones by increasing the picture contrast.

DESCRIPTION OF THE INVENTION

The invention relates to the field of refining weakly colored varieties of mineral chalcedony group to improve their artistic and decorative properties and can be used in the manufacture of jewelry.

There is a method of processing gemstones chalcedony group and their products, to enhance the decoration, by increasing the brightness of the stones, according to which the finished product is kept at a temperature of 400-600 o in an oxygen atmosphere [1]. However, the application of this method involves the use of sophisticated equipment, allowing to create high temperatures and oxygen atmosphere.

The closest to the proposed method is providing for staining white agate under hydrothermal conditions. The process is carried out in aqueous solutions of salts or sugars containing coloring metal ions at 150-350 o C and a pressure of 50-400 atm for 5-20 hours. [2].

The aim of the invention is to provide gemstones chalcedony group with enhanced decorative effect by increasing the brightness of the stones by increasing the picture contrast.

This object is achieved in that the sample is placed in a solution of 5-35% alkali (LiOH, NaOH, KOH). Treatment is carried out under hydrothermal conditions at T-50-300 o C and P-50-500 atm for 5-25 hours.

When the concentration of the alkaline solution <5% of the sample leaching process is very slow and the appearance of the samples can be changed only after prolonged treatment. When the concentration of the alkaline solution> 35% is an active interaction with the sample solution, which leads to embrittlement of the sample. For the same reasons, the creation of a temperature> 50 o C and pressure> 50 atm is necessary to increase the speed of interaction with the sample solution. To conduct the experiments at lower T and P values ​​are not rational because of reduced processing speed. The increase in T> 300 o C and P> 500 atm not possible due to the appearance of the fragility of the samples with the active leaching.

Hydrothermal method allows you to create and manage the necessary temperature and pressure. Experiments carried out under hydrothermal conditions in standard autoclaves lined with PTFE liners that serve as protection for the material from the corrosive environment of the autoclave. At the same time the use of airtight digesters is reliable protection against chemicals and exposure to alkaline vapor to the environment.

The method is as follows. Alkaline solutions are easy to take out large amounts of silica from chalcedony and its varieties. This is due to the fact that the chalcedony in the spaces between the fibers of quartz contains opal, which is easily leached. The individual layers of chalcedony have different and characteristic for their resistance to dissolution.

As a result, mineral processing revealed very contrasting picture in the solutions listed above, the inherent agate, which improves their artistic and decorative properties.

example 1
The pre-polished sample is processed as follows: in the vessel (standard autoclave) with PTFE liner prepared 35% solution of KOH. Samples were immersed in solution, the vessel (autoclave) was sealed and heated at 50 o C, the pressure in the vessel is 50 atm. After exposure 5 hours. samples are removed from the solution, washed in H 2 O and dried at room temperature for 5-15 min. The samples were then subjected to a final fine grinding and polishing.

example 2
Analogously to Example 1, except that the samples are processed in a 5% KOH solution and maintained at T-300 o C and P-500 atm for 10 hours.

example 3
Analogously to Example 1, except that the samples are processed in a solution of 10% LiOH, and kept for 25 h. with T-300 o C and P-500 atm.

example 4
Analogously to Example 1, except that the samples are processed in a solution of 20% NaOH and kept for 20 hours in T-200 o C and P-200 atm.

Using the present invention provides a contrast detection pattern inherent agate, even if it is difficult to see in the original stone, but also it is possible to effectively use low-grade agate, which will enhance the possibility of the jewelry industry in the selection of raw materials and will give a significant economic impact. In addition, the use of hydrothermal method allows you to create protection from aggressive alkalis, reducing the harmful effects of chemicals on the environment.

INFORMATION SOURCES

1. Author's certificate USSR N 566621, cl. B 01 J 17/00, 1977.

2. Japanese Patent 40-17656, cl. 13 EA 1968 (prototype).

CLAIM

A method of treating ornamental stones chalcedony group, comprising treating under high pressure and temperature, chemical reagents, wherein the sample is ground and incubated in alkaline solution LiOH, NaOH, KOH at a temperature of 50-300 o C and a pressure of 50-500 atm for 5 -25 h.

print version
Publication date 02.01.2007gg