Your cheaper lab grown synthetic ruby could probably be flame
fusion type i.e. Verneuil synthetic ruby. It is much cheaper to
produce and has been around (as someone has mentioned since late
1800’s and beginning of 1900’s). Flame fusion ruby could be
differentiated from the Chatham or Russian Flux grown ruby is by
their inclusions or certain growth marking. The Verneuil synthetic
ruby would show a curved striation growth marking with some gas
bubbles. Whereas Chatham flux grown ruby would show wispy-veil
growth marking which is rather unique because these grown marking
are residue of the flux material. Sometime you may come across
platinum platelet inside the Chatham synthetic ruby as they use
platinum crucible for their growth process. Occasionally, some
Chatham synthetic ruby could give rise to problem in identification
especially when the wispy-veil may exhibit a look alike healed
fissures found in natural ruby. It is best that you try and read
up the classic reference book on ‘Photoatlas of inclusions in
Gemstones’ by Dr. E. Gubelin and Mr. J. Koivula; ‘Gem Testing’ by
B.W. Anderson; ‘Handbook of Gem Identification’ by R.T. Liddicoat.
The subject of gem identification is too wide a subject to be
discuss in here and my simple advice is to read up, cross check with
gemologist and hand-on experience. Good luck to you.
Tay
Singapore
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