What stones are untreated?

[hatsumomo]

As a beginning collector, I am very nervous and confused about acceptable treatments for gemstones so I have decided to start by focusing on gems that are never treated until I start to feel comfortable. I know spinel, tsavorite garnet, and rubellite are never treated but what other stones can I look for? Is Beryl (other than emerald) ever treated? Thanks so much!

 

[T L]

As a beginning collector, I am very nervous and confused about acceptable treatments for gemstones so I have decided to start by focusing on gems that are never treated until I start to feel comfortable. I know spinel, tsavorite garnet, and rubellite are never treated but what other stones can I look for? Is Beryl (other than emerald) ever treated? Thanks so much!

The tourmalines, which rubellite is part of, are occassionally heated and/or irradiated.

Aquamarine is routinely heated (part of the beryl family)

Morganite is also treated, but I forget if it undergoes heating or irradiation (a beryl).

I believe Heliodor (a yellow beryl) is irradiated.

The only gems I can think of that are not treated, or at least not commonly treated at this time, are

spinels
garnets (except for demantoid)
chrysoberyl (the transparent gem, not the cat's eye stone)
alexandrite (part of the chrysoberyl family)


Other than that, and besides some very rare exotic gems, those are all I can think of right now that remain untreated. The status of treated gems is changing all the time. I have some books from around 20 years ago where some of the gems that are commonly treated now, are specified as an untreated species back then. It's rather sad, and then you have synthetics and simulants to worry about besides treatment. I don't mind treatment if it was always disclosed, but this is usually not the case.

 

[Arkteia]

Andalusite, I think
Sphene
Sphalerite
Taaffeite
pezzotaite

 

[PrecisionGem]

Not Treated:
Oregon sunstone

 

[blithesome71]

My personal favorite, PERIDOT

 

[hatsumomo]

Thanks for your continued input. I've realized that there are very few untreated stones! It's very difficult to become knowledgeable without any standard grading and when some vendors do not give full disclosure.

If I were to consider stones that are sometimes treated, who would you recommend buying from and a newbie? I've been looking at Steve Perry's site and it seems like a good place to start. Is this right or do you have other suggestions?
Also, does anyone have experience buying from him?

 

[Lee Little]

Watch out for Ted.
http://themelis.com/Gem-new.html

 

[chrono]

I wouldn’t say never but as of now, there are still a few varieties of untreated gemstones.
Spinel – attempts have been made to heating them without much success.
Tsavorite and spessartite are still untreated. That said, I have seen clarity filling of garnets.
Rubellite is now heavily treated, heated to remove colour, then irradiated for that super hot saturated colour which is currently not detectable by labs.
Many stones in the beryl family are treated.

Remember that not everyone will view treatment the way some PSers do. Treatment improves clarity and colour, and makes some very expensive stones affordable. It also widens the pool of saleable stones. That said, it is very important to have that treatment disclosure upfront AND the pricing has to reflect the treatment. There are some frequently recommended vendors like www.acstones.com , www.PrecisionGem.com , www.thegemtrader.com , www.ajsgems.com , and more in the recommended vendor link at the start of the CS page (one of the stickies).

 

[hatsumomo]

Watch out for Ted.
http://themelis.com/Gem-new.html

Thanks Lee Little, this is exactly what I'm afraid of. Given that I'm a beginner (with a strong interest in learning!) I don't know enough to make good judgments about such murky areas of the colored stone world. I know that its not so simple to be cut and dry, and takes a lot of time and experience to be proficient in the language of gemstones but I have to start developing my connoisseurship somewhere.

I just want to start buying from sources where I know what I'm getting, where I can buy quality, and where the vendor has my satisfaction at heart because if I trust them I will continue to buy from them.

 

[hatsumomo]

Thanks Chrono. This helps narrow it down. I did take a look at the list of vendors but I didn't know which were recommended and which would be the easiest and most transparent in their dealings for a beginner who is interested in growing into a serious collector.

I look forward to more of your testimonials and good guidance!

 

[KarenFe]

This is good and helpful information. Thank you!

 

[hatsumomo]

OMG, I never heard of sphene before but it is extraordinarily beautiful! I think I have to own some. Does anyone own any? If so, who did you buy from? Thanks

 

[hatsumomo]

OMG, I never heard of sphene before but it is extraordinarily beautiful! I think I have to own some. Does anyone own any? If so, who did you buy from? Thanks

They are currently showing it on JTV but I've been warned not to shop from there.

 

[chrono]

I have a sphene but dare not have it set. Sphene is extremely beautiful and dispersive (see Arcadian's avatar) but a rather fragile stone not suited to daily wear. It's not something I'd wear in a ring either but some PSers have more guts than I.

 

[T L]

OMG, I never heard of sphene before but it is extraordinarily beautiful! I think I have to own some. Does anyone own any? If so, who did you buy from? Thanks

I bought mine on ebay from a dealer called "exportgems." I think some others have purchased sphene from him too. I wouldn't buy corundum and some other stones from him, but I think he's safe for sphene. I also have a six carat scissor cut that doesn't really show off the dispersion as I would like, but it has beautiful apple green base color. I'm considering a recut on it. I bought it a very long time ago.

I think LD bought her amazing sphene from Multicolour.com, but be careful, he has lots of different quality, and you get what you pay for.

 

[hatsumomo]

I'm fearful of making a first purchase online considering that many online dealers get pretty mixed reviews. Also, unlike white diamonds, it doesn't seem there is a huge savings between buying cs online v b&m. Since I live in NYC, could you recommend any dealers in the diamond district where I could examine stones in person? I shopped and considered but didn't end up buying my diamond e-ring in the DD but I wonder if it would make sense for colored stones.

 

[T L]

I'm fearful of making a first purchase online considering that many online dealers get pretty mixed reviews. Also, unlike white diamonds, it doesn't seem there is a huge savings between buying cs online v b&m. Since I live in NYC, could you recommend any dealers in the diamond district where I could examine stones in person? I shopped and considered but didn't end up buying my diamond e-ring in the DD but I wonder if it would make sense for colored stones.

I don't know where you would see a sphene at the diamond district, but if there are any large gem shows that come to your area, I would go there. They tend to specialize in exotic gems.

 

[LD]

Actually you're far safer buying from one of the vendors in the sticky list at the top of this part of the forum. Most of them have very good returns policy also.

The type of coloured gemstones you see in shops are rubies, sapphires, citrines, amethyst, opals, topaz and occasionally tanzanite. However, they are very rarely specialists and are mostly jewellers who deal in diamonds with coloured gemstones as an after-thought. So what you typically find is that they won't be aware of treatments OR will have bought without having something tested OR will know about some treatments but not all. Of course that's a sweeping generalisation. However, if you go to a coloured gemstone vendor, it's in their interest to be upfront about each gemstone because that (hopefully) keeps you coming back for more.

Look at the following websites to get ideas about what you like and these vendors are always helpful and willing to give you lots of advice so you make an informed purchase - they also disclose treatment. In no particular order:-

John at Gemrite
Gene at Precision Gems
Dana at Master Cut Gems
Brad at The Gem Trader
Rung or Arnold at AJS Gems
David at Multicolour Gems (enquiries go to a general mailbox and it sometimes takes a while to come back to you)
Barry at ACS
Eric at Swala Gems
Ed at Wildfishgems
John at Simplysapphires

One thing to be aware of it that typically you pay for what you get. So if something is lower in price than you would expect there's normally a reason!

 

[T L]

Actually you're far safer buying from one of the vendors in the sticky list at the top of this part of the forum. Most of them have very good returns policy also.

I would just add to this to always check the return policy with any of these vendors, as they could have changed since they were last recommended. Also, depending on where you live, overseas dealers might be a lot more difficult to return items too. I would stay with domestic sellers if you're truly worried about returns.

 

[LD]

Sorry - something else for you to be aware of. Some "treatments" are standard and expected i.e. heating of Tanzanite, oiling of Emeralds etc.

There are also levels of treatments:-

1. Totally natural
2. Heated only
3. Treated such as filling, dying, reconstituting, BE diffusion, irradiation etc

The most expensive (and most difficult to source typically) are those that fall into the first category. Slightly behind that (and still difficult to source) are #2. Some people tolerate heat only as this is something that may have occurred naturally in the earth. Others believe that it's interfering with nature. You've got to decide on your own tolerance level.

Here are some that can fall into 1 and 2 above BUT be warned that new treatments are popping up all the time!

Garnet (except Demantoid)
Iolite
Peridot
Clinohumite
Diopside (I think)
Jasper (some not all)
Agate
Kyanite
Moldavite
Opals (some not all)
Prehnite
Scapolite (some colours - not all)
Tourmaline (some - not all)
Sphene
Spinel
Pezzottaite (I think but there's something in the back of my mind that's making me hesitate about this one)
Quartz (some not all eg Citrine, Amethyst, Ametrine etc)
Chrysoberyl (some not all)
Alexandrite (some not all - there's some evidence that they're now being filled)

 

[T L]

I know they're irradiating purple scapolite now, and maybe some other colors as well.

Tourmalines are also subject to irradiation and clarity enhancement.

Also diamonds, the #1 gemstone sold, are subject to irradiation, synthesizing, simulants, clarity enhancement, and coating. They've got it all.

 

[Pandora II]

Add to the great vendors:

Rick Martin at Art Cut Gems

A few words of warning on a couple of stones listed:

Sphene - the really great ones in big sizes aren't super cheap and it really isn't a ring stone IMHO. I have set three in a pendant and earrings, but I used a really simple prong setting and felt sick till I got the call that they were safely done. I only wear them on special occasions. One of my favourite gemstones though.

Sphalerite - trying to set this would probably give me a heart attack - I'm sure someone has done it but IMHO it's a stone for a box not for wearing: soft and with perfect cleavage. At 3.5 - 4 on the Mohs, common or garden dust is going to scratch this (most dust is a 5 on the Mohs).

Peridot - these are very easy to chip chunks off due to their cleavage. Also, unlike most gemstones (not including organics) they react to acids. My gemmology tutor dipped one in the UK leading brand of household cleaner for 20 seconds and did before and after photos - the result was truly horrific.

Iolite - hard to find nice ones but when you do they're lovely and can look very tanzanity - but most have a strong greyish yellow look due to their strong pleochroism. They're also a bugger when it comes to setting as they have very strong cleavage and can break very easily.

Taaffeite - super rare and very expensive. Ditto Alexandrite.

Kyanite and Clinohumite are also rare and soft - a 6 for clinohumite and Kyanite is a weird one where the hardness is directional: 4.5 - 5 parallel to one optic axis and 6.5 - 7 perpendicular to it. Add to that two directions of cleavage and I'm running for the hills. Both are very pretty though.

One stone I am liking a lot at the moment and am about to go hunting for some really nice ones is Andalusite. It's a 6.5-7 on the Mohs, but no cleavage. It's very dispersive and has what almost looks like a play of colour with red, green and yellow due to its very strong pleochroism. It's lovely and bright and sparkly although finding an attractive body colour isn't that easy. I keep coming across them and they leap out at me.

Garnets are my big thing and other than demantoid I consider them all suitable for careful wear. My general rule on wearing coloured stones is that they come off if you are doing anything much with your hands - no housework, gardening, cooking, sleeping (bad for prongs) or other dangerous things. My e-ring is a tsav and even though I only wear it when I'm going out and I'm very careful with my hands, I've still managed to get a tiny chip and a scratch.

Treatments:
My personal lines on treatments: (with all of these I like disclosure and to pay the right amount).

Sapphires - heat is fine, Be diffusion or similar is not.
Rubies - I'm steering clear for now. Heat is fine, but no lead-glass filling or diffusion
Emeralds - oiling 100% fine and I'm okay with Opticon but want more info on any other fillers.
Zircon - heat is fine.
Tanzanite - heat is fine
Demantoid - heat is fine.

I don't like any stones that have been nuked by man - so blue topaz is out, rubellite tourmaline I'm leery about for now. I also don't care for stones made of unattractive bits of quartz turned into 'green amethyst' or citrine.

For a starter collection I would go with garnets, spinels or tourmalines and then start branching out.

 

[Lee Little]

Is there really a variety of gems that is never treated? I do not think so!
There are certainly those that are are sometimes not treated but we can never say never. Best regards, Lee

 

[T L]

Is there really a variety of gems that is never treated? I do not think so!
There are certainly those that are are sometimes not treated but we can never say never. Best regards, Lee

I agree Lee. I sometimes say "typically not treated, or uncommonly treated" and if I say "never treated" I hope someone corrects me.

 

[blithesome71]

Peridot - these are very easy to chip chunks off due to their cleavage. Also, unlike most gemstones (not including organics) they react to acids. My gemmology tutor dipped one in the UK leading brand of household cleaner for 20 seconds and did before and after photos - the result was truly horrific.

Is this true? I hope u could post some pics... 'cos I've tried to use a soft brush & a dish washing liquid to clean one of my peridots. So far it didn't change its look and luster...

 

[chrono]

Blithe,
You are fine with dishwashing liquid. Many household cleaners contain harsh chemicals like ammonia and other acidic substances.

 

[blithesome71]

Chrono & Pandora,

Thanks for that helpful info. I'll be extra cautious when it comes to cleaning my gems (esp. peridot).
This is what's good about PS, I learn new info & tips. Keep it up u guys