Testing of Burton's method to synthesize diamonds
A method was investigated to synthesize diamonds at atmospheric pressure without the use of diamond seed crystals. The method was first proposed by Burton in 1905 and appears to have been lost in the literature. The procedure is based on Ostwald's principle of the formation of metastable, intermediate crystals en route to a more-stable final product. Carbon was dissolved in a lead-calcium alloy and was later precipitated out of the melt by the removal of calcium with steam. The calcium was used to increase the solubility of carbon in lead. Reaction temperatures between 775 K and 1025 K were used. The resulting precipitate, analyzed by both chemical and physical means, was found to be well-crystallized graphite. No diamond formation was found to occur.