In 1877, Fremi, a French chemist, used pure alumina powder, potassium carbonate, barium fluoride and a small amount of potassium bichromate as raw materials. After 8 days of high temperature melting in a crucible, small ruby crystals were obtained, which was the beginning of artificial ruby.
In 1900, scientists used aluminum oxide after melting a small amount of chromium oxide, Cr2O3, according to the weight ratio of 0. With 7% added method, 2g~ 4g rubies were produced. Today, rubies and sapphires as large as 10 grams can be made.
In 1885, some high-quality artificial rubies appeared in Geneva, Switzerland. It is said that there are natural ruby fragments, plus the red potassium dichromate and other high temperature melting made, and the nature of the natural products. However, it was the French chemist Verneuil who actually made the gemstone and put it into large-scale production.
In 1891, Verneuer invented the process of flame melting and used it to make artificial gems. After success, he experimented with pure alumina. The test was carried out in a high temperature Muffle furnace with an inverted hydrogen and oxygen blow pipe. The fine powder of pure alumina containing a small amount of chromium oxide was slowly dropped into the flame and melted, dripping on the base to condense and crystallize. After ten years of hard work.
Artificial rubies were made by Vernayet in 1904, and since then flame melting has been perfected to produce rubies almost indistinguishable from natural ones. This method has been used until modern times and is still the main method of producing artificial gems in the world, known as “Verneuil method”. Now it only takes a few hours to produce more than 100 carats of ruby raw stone, artificial corundum crystals with the appearance of pear shape or carrot shape, pure texture, color transparency even more than natural products, and huge economic benefits. The modern Verneuil process not only produces rubies ranging from light pink to deep red, but also sapphires of various colors, and even rubies and sapphires with starlight. It is a miracle.