Tension setting opinions on price, and are they diamond only?

[Moosejaw]

I have read varying responses from previous posts regarding tension settings for stones other than diamonds. Does anyone have an opinion of a garnet at 7-7.5 being set in a tension setting?

I also wanted to get opinions on quality vs. name...i.e. Ketchmer vs. knockoffs?

Is there a difference other than price? I am aware that the brand name will always tell you there is a difference, but when youre talking the difference between 2-4k...I'd like some professional opinions.

Thanks,

G

I wanted to attach a photo but it aint working...but its in the colored gemstone gallery...the triangle spessartite.

 

[Sundial]

For what it is worth, I recently had a discussion with my local jeweler (who has been in the business for many years) about which stones he would recommend for a tension setting. He said he would only use diamonds, sapphires, or rubies. To me it would be worth it to go with a branded setting from someone who specializes in tension settings, but I am not a professional.

 

[Adylon]

I''m biased to certain brands of tension rings but I won''t mention them because it''s not appropriate But I understand your questions and I''ll try to be as helpful as possible.... if someone is willing to set a garnet I''d be a little suspicious to be honest with you because it''s not a very hard stone (it''s a lot better then say fluorite or tanzanite) but most of the tension manufacturers have policies that they will only set diamonds or cleaner sapphire/ruby due to the high tensile loads. I suppose it may be possible to set garnet in a tension ring but you''d probably want to alter the design to have a lot of contact patch holding the stone over a very broad width and cross sectional area, thus decreasing the overall average psi compressive load on the stone. Imagine for example 1 tension ring holding the stone at 2 very sharp points and another holding the stone over a 10mm ring width and holding more of the stone then just the girdle. If you applied 100lbs of force on the one being held at the 2 sharp points vs. the other ring, obviously that one would be putting a lot more stress on the stone and it would be much more likely to fracture.

Some manufactuers make tension settings that hold a lot of force, some not so much. They do this by using proprietary methods of manufacturing with heat treatment, work hardening, exotic alloy mixtures, etc... and some just set it as cast in regular 14K, 18K, etc. Some use very lightweight mountings and some use real heavy duty mountings which are less likely to deform due to every day wear. So be sure to compare apples to apples.

 

[angeline]

As someone that is very partial to tension settings... may I say, fabulous answer Adylon! I think Moosejaw that you should be wary of regular jewelers trying to do tension without hardening the metal in some way. The metal needs this to provide enough spring in it to compress against the stone to hold it in. I think titanium is the only metal that doesn''t require special processing to use in a tension setting.

There are lots of look-a-like tension settings that have a ''bridge'' under them, sometimes called suspension settings. These aren''t true tension as the bridge provides the force to hold the stone in place if you know what I mean, it completes the circle.

Tension manufacturers that you can trust imho are Kretchmer, Niessing, Gelin and Abaci.. there may well be others that I haven''t heard of.

HTH!

a

 

[denverappraiser]

A garnet set into a compression setting like one of the Kretchmer designs you’re considering would pop like a pimple. There’s a good reason that the mainline manufacturers will only set a diamond, ruby or sapphire and they tend to be downright picky about even that.

Neil Beaty
GG(GIA) ICGA(AGS) NAJA
Professional Appraisals in Denver

 

[:)]

Kretchmer uses one of the patented blends which makes his alloy well suited for tensions.

 

[Adylon]

I bet you one of the major manufacturers of tension rings listed above COULD make it work if you really wanted it badly enough. Problem is there is no way they would gaurantee anything, plus well, you''d have to send them 3-4 stones to play with and assume 1/2 or more will break I''d give it a 50/50 chance they could make one of them work out of 3-4 stones... but the good news is if they could make it work, once it''s set you''d probably never have to worry about it again.

 

[Moosejaw]

Thanks for all the great advice. It looks like a suspension setting might be a much better idea, although I love the tension settings. I was hoping someone might say its possible...with no risk.



-G

 

[N8-Star]

Moosejaw, I was also interested in getting an Amethyst set in a tension setting as well... In my experience, I found that most manufacturers will not tension set a stone less than a 9 on Moh''s hardness scale ( link ). However, synthetic stones are not a problem.