Gemstones from melts

The most frequently used techniques for the commercial manufacture of synthetic gemstone materials are summarized in Table 4. More details on these can be found in various texts (2,5—7). An overview including the various manufacturers is also available (3). Only rardy used for synthetics are such alternative growth techniques as the Bridgman technique of solidification in a cmcible and the float zone technique, both involving growth from the melt... 

The flame fusion process was the first method to give crystals of acceptable size for commercial applications from the melt, namely ruby crystals for use as gemstones. 

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