Post subject: Re: HOW GOOD ARE SYNTHETIC SAPPHIRES IN 2021?
Posted: Tue Mar 30, 2021 1:56 pm
Gold Member
Joined: Tue Apr 05, 2016 7:58 pm Posts: 1424 Location: San Marcos, CA
S. Rautiainen wrote:
glhays wrote:
is there or was there a time when the processes of making synthetic corundums, where the lab is not using the color agent to produce the property's of red shades and or blue shades. Or is that thinking more where the commercial side has taken it?
I'm not sure if I completely understand this question but rubies were one of the first stones to be man-made and the processes in how to make them have just improved/changed over the years. Ruby is coloured by chromium, both naturally and in lab-created versions so that hasn't changed at all but when the processes where first coming out they weren't making white sapphires or other colour variations as there was a much higher demand to the standard blue sapphires and rubies. Nowadays I'm sure it's still true that people still look for ruby or blue sapphire but the other colours are becoming better known and I have had some people bring in / talk about / ask for those other colour both natural and synthetic.
Steve already answered my bewilderment of the OP's statements, and as well so did the Op. White sapphires? In some circles that term can get you placed on a scamologists list.
Post subject: Re: HOW GOOD ARE SYNTHETIC SAPPHIRES IN 2021?
Posted: Tue Mar 30, 2021 3:13 pm
Site Admin
Joined: Sun Oct 16, 2005 12:22 pm Posts: 21602 Location: San Francisco
An FYI post:: Random Neural Firing
White, or colorless synthetic sapphires can be separated by transmission (or lack thereof) of SWUV. I believe I first heard it from Thierry Pradat and Dr. Hanneman and then later the GIA posted an article by Emanuel Fritsch:
Shane Elen and Emmanuel Fritsch wrote:
Greater amounts of colorless sapphire—promoted primarily as diamond substitutes, but also as natural gemstones—have been seen in the gem market during the past decade. In the absence of inclusions or readily identifiable growth structures, natural colorless sapphires can be separated from their synthetic counterparts by their trace-element composition and short-wave ultraviolet (SWUV) transparency. Energy-dispersive X-ray fluorescence (EDXRF) analysis shows higher concentrations of trace elements (i.e., Fe, Ti, Ca, and Ga) in natural sapphires. These impurities cause a reduction in SWUV transparency that can be detected by UV-visible spectrophotometry (i.e., a total absorption in the UV region below 280–300 nm, which is not seen in their synthetic counterparts). This article describes a SWUV transparency tester that can rapidly identify parcels of colorless sapphires.
Synthetic sapphires are usually coloured with iron and titanium compared to those that are found naturally where they are almost always just coloured by iron.
You may want to double check that. In particular look into the trace element differences between the classic metamorphic, non classic metamorphic, and magmatic origins of blue sapphire.
The classic colored blue metamorphic sapphires tend to be relatively titanium rich and iron poor. This is one reason they respond so well to heat treatment. The magmatic sapphires mostly also contain titanium but are over saturated in iron. That is why they are so dark, the blue color is tainted by green and don't respond to treatment as well.
Sorry, you are absolutely correct, thanks for reminding me. I was remembering something else obviously, maybe it was another synthetic blue stone or a different element. I'll go grab my notes when I'm back home and see what it was.
Thanks for the link on the history though Barbra. I'll make sure to save it for later whenever people bring in their parents jewellery and they say it must be real because it was from the 1940s...
Post subject: Re: HOW GOOD ARE SYNTHETIC SAPPHIRES IN 2021?
Posted: Tue Apr 06, 2021 3:15 am
Gold Member
Joined: Tue Apr 05, 2016 7:58 pm Posts: 1424 Location: San Marcos, CA
There was a group a few years back that decided they were going to rid the internet of people they believed by certain use of gemological gem descriptions were scammers and had started a list that potential buyers would be able check. Using the term "white" to describe colorless gems in their opinion was deceptive and you were potentially a scammer. So if you described a product to have White Topaz, White Sapphire, White Quartz. We gave little attention to it in our business, as we know it is a common naming convention. Not going to mention names here, not really sure but I think they have been put in check by the industry.
Ohhhhhh! Yeah I ran into someone like that one facebook once (though he was pretty quickly laughed out of the group for that and other things). These people obviously didn't read The Hobbit. Heaven forfend that one of these innocent buyers looking for an opaque white topaz or sapphire be tricked into buying something transparent!
Post subject: Re: HOW GOOD ARE SYNTHETIC SAPPHIRES IN 2021?
Posted: Tue Apr 06, 2021 5:22 pm
Gold Member
Joined: Tue Apr 05, 2016 7:58 pm Posts: 1424 Location: San Marcos, CA
Yep, probably the same group. If I remember right a prominent member of the industry had them in a legal dilemma. Like I said we kind of brushed it off as they will find out, that is not going to get them much notoriety in the trade.
Users browsing this forum: No registered users and 15 guests
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot post attachments in this forum