Determining the hardness of a sea- blue colored stone.

[jimmorrow]

Hi Everyone,

Im new here, so my question might be rather boring, and amateur, but i thought i might get an answer here.

I have a large, blue colored uncut stone left from my family and i am trying to identify it under domestic conditions, in order to find out weather its worthy sending it for certification at all.

Ive been reading a lot of comparisons between tools determining the hardness of stones and everyday items, and i thought i might manage to determine weather its hardness is over, or equal 7.

The stone scratches window, jar, and bottle glass, as well as ceramic tiles, but it gets scratched by a high quality ice hardened steel knife. I even found an old watch with supposedly quartz glass and it gets also scratched by the stone.

I would very appreciate it if i hear Your thoughts regarding the possible hardness of the stone.

Thanks in advance!

 

[chrono]

Re: Determing the hardness of a sea- blue colored stone.

Why are you trying to damage both the unknown object and other household items? Hardness does not tell you much. If you must, one of the cheap thermal conductivity tester is a first start (most jewellery shops have them). A better test is of course, to find out the refractive index.

 

[jimmorrow]

Thanks for Your response, Chrono,

I guess i have fully deserved Your sarcasm .

The reason i am playing a gemologist home is, that i had a strange experience sending a piece of the stone to a lab, and i received no answer from them. What happened is, that a piece of the stone chopped off after it fell on the ceramic tile floor, and i sent that piece to a friend of mine, who works in a gemological lab, with the idea to get it identified. After that piece chopped off, the stone seems to be wrapped up in some kind of stuff, which oxydizes strong. The stone has been found inside a rock. The inner part of the stone is absolutely clear light blue.

The day after he took it, he called me and said that the piece was shown to a professor gemologist, who said that it was an aquamarine, or a tourmaline, but it reacted more as a tourmaline, whatever that means. He told me, that, in order to determine it exactly, it needs to go through x-ray examination, in order the crystalline structure to be determined. I stressed on the fact, that i really need that piece back, because i wanted to send it to GIA for identification, and he said that ofcourse he would send it back to me.

What happened next was, that i waited for more than a month for a call from him. After i called him with the question what happened woth the x ray, he told me, that it had shown NO crystalline structure at all. After i said ok, please, send the piece back to me, he told me that they had to crash it to powder in order to examine it with x rays, and it had been destroyed- something, that does not make any sense to me. Why destroy the thing, that u examine, when the client had insisted on having it back???

Maybe ill start a new topic describing that case, but id be more than grateful to hear what u think about it.

Thanks!

 

[chrono]

Wow, that's really weird. A stone should never be destroyed in an attempt to verify or find out what it is! I wouldn't send anything else to that professor. Really, if the usual labs we send stones to do this, I'd never have any pretty rocks left to keep.

 

[jimmorrow]

Thats how the item looks like.

 

[Sphene]

How big was the piece you sent off?

 

[jimmorrow]

the piece was about 5 cts

it was part of the oxydized 'crust' surrounding the clear stone, as well as a part of the clear part of the stone attached underneath.

 

[pinkgem2522]

wow thats a big piece of rock you got there!

 

[jimmorrow]

any thoughts on what that might be, or suggestions how i can find out weather its simply glass, or something more under domestic conditions? anybody?

 

[PrecisionGem]

Do the tongue test. If it feels cold to your tongue, its most likely a mineral, if warm, then it's most likely glass.