could not resist saying one more thing again… to roy john, you are quite an expert to do what you’re doing…anyone without your experience and knowledge could lose their pants buying rough and cut sight virtually unseen from dealers in thrid world countries.
to everyone else: what a great discussion!..and what a great website we have…people from all backgrounds, from beginner leve to commercial artists in metal and stone contribute freely of their knowledge and experience, often hard won by trial and error (making a mistake is a very good teacher!)…the tips are invaluable to eveyone no matter what their level of expertise is…I’m enjoying the interchange of ideas from a distance now but am glad to know that the community is thriving. Thanks to the moderators who keep discussions on track and calm and collected… I don’t have a lot of practicality to contribute anymore, having been out of it for decades but will contribute what I can…sometimes the science behind the topic is very useful in understanding the properties of gems and metals…cost benefit comments are very helpful too… the cost of capital equipment versus “jury rigging” to satisfaction factors in also… what’s appropriate and affordable to the home hobbist beginner is different from commerical production and sale for profit. Those who engage in the latter have their own problems too because of the opacity and wild fluctuations in the market for both raw and finished products…I’ve found all of the forums and posts to be engaging, practical, and of great utility to anyone who is making jewelry at any level of experience and expertise…thanks for the engagement to all.
3 Likes
Since I last posted, I joined the IGS website as a gem enthusiast. It’s extremely helpful, although some aspects are very basic…the price range for natural and synthetic stones have a wide range.
Roy John is absolutely right in stating than synthetic diamonds do have characteristic inclusions. Those that are grown in presses haves iron inclusions due to an iron catalyst/diffuser for the carbon atoms that attach to the seed. Using an iron diffuser speeds up the crystal growth process so that it takes less than a year, sometimes as short was a few months to grow a diamond. The other technique is vapor deposition, which creates diamonds in interplanetary space naturally… these have planar growth lines. After General Electric was able to produce the first high pressure temperature diamonds, some were grown from pure graphite, without a catalyst. It took 2-3 years to produce a gem diamond at 7-10 Gigapascals, a higher pressure than current production and at a slightly higher temperature… as the starting materials were pure, Type II diamonds were synthesized, pure carbon that were indistinguishable from natural by all physical and chemical methods. Present day commercial production by either high PT or vapor deposition can be speeded up to make industrial grade microdiamonds used in abrasives and cutting tools. Nitrogen as in Type I diamonds are now added to speed up growth in presses… most of the market for synthetic diamonds goes to industrial uses… estimated over 90%. Synthetic diamonds as currently produced for the gem market can be distinguished from natural by physical and optical techniques, including looking for metal catalyst inclusions by microscopy and by spectroscopic and fluorescent techniques…the latter two do not require cost prohibitive laboratory equipment but are still specialized.
Colored stones can be grown by either flux fusion or hydrothermal methods… the latter is more expensive and slow in general, as high pressure and high temperatures are need for longer period of time. Synthetic quartz can only be grown hydrothermally. Flux fusion stones can be distinguished by flux inclusions which are white, hydrothermal by “fingerprint” and growth lines that are not natural. The only equipment needed is a microscope.
Being able to distinguish lab created from natural by easy techniques by professionals is all very reassuring.
4 Likes
Just wanted to comment on what @KimberlyJ67083 said about (
…tourmalines were an alternate to more expensive colored stones but I did buy a pair of 10 carat hot pink ones from a local gem dealer in the Pala area of California, near Julian… )
I used to live in Valley Center near Mt. Palamar
Pala tourmaline mines, world famous!
Also what an informative read thanks to all the contributors.
I read somewhere that the structure of man made ruby’s and emeralds is very organized and that natural we’re not.
Thank you
Steven
Hi,
Here is a youtube link to a talk on lab grown diamonds that i found interesting and informative….I thought i would share…
talk given by ADA Diamonds at GIA
julie
2 Likes
I also bought a pair of hot pink Palas of 5- 6 ct size… good quality and color, loupe clean… any idea of how much they are worth now… got them years ago for $500. I suspect gem prices have gone around 10 fold since I bought them.
thanks for sharing. I am finding the GIA website far more informative than what is on the GIS, the latter being more suited to beginners. The GIA has done an incredible amount of research into lab grown stones over the last couple of years… in addition, West African stones in particular are sold in mixed lots with many other sources mixed in. Provenance has been a problem with these stones, but the GIA is doing a lot more research now. Two years ago, I attended a GIA presentation on West African sapphires. By using both minimally destructive (laser ablation) and non destructive techniques, there were able to determine provenance by the trace element signatures of the stones. Some of the research techniques involved specialized equipment, particularly mass spect. Technological advances have been keeping pace with the growing market for gemstones… The GIA’s stated mission was to detect fraud and bring order to the gem market. They are keeping one step ahead now in both the natural and lab created gem markets.
lab created corundum and emerald stones can be grown by flux fusion or by hydrothermal methods. Both leave characteristic inclusions and grow lines that can distinquish them from natural and each lab grown method. It’s reassuring that the GIA has investigated and continues to investigate lab grown stones of all kinds.
