I think it's a yellow sapphire????

[Grace O'Malley]

We found this in Helena National Forrest in Montana back in July. I fished it out of a creek while I was looking for gold nuggets.
Could it be a yellow sapphire?

[Grace O'Malley]

Oh yeah, it weighs 9.1 grams.

[Eu_citzen]

More likely quartz.

[lamplighter36]

It would be cool if it was!

You can always read up on the Moh's scratch test and rule out sapphire. Might be a fun process. Beautiful find.

-Thomas

[MRBeyer]

If it is soft it may be calcite. Myself, from the melted glass look to it, looks like the raw blue sapphires I have. Good luck, nice find. You might want to mark where you found it at so you can go back. 6 grams is nothing to sneeze at, nor it being a tangerine sapphire.

[Goodyguy]

Diamond has a hardness of 10
Sapphire 9 .........Wont be able to scratch it with a steel knife point
Quartz 7 ............Should be able to scratch it with a steel knife point
Calcite 3 ...........Should be able to scratch it with a copper penny

GG~

[Grace O'Malley]

Well, I got the lesche out and there is no way it would ever make even a tiny scratch on this rock. I think you could whack it with a hammer and the rock would win. Not that I would be brave enough to try it....
If it is a tangerine sapphire, how much would one this size be worth? I've never seen one this big on Feebay.

[Goodyguy]

Well, I got the lesche out and there is no way it would ever make even a tiny scratch on this rock. I think you could whack it with a hammer and the rock would win. Not that I would be brave enough to try it....
If it is a tangerine sapphire, how much would one this size be worth? I've never seen one this big on Feebay.

Depends on cut and clarity, but it would be worth a lot more after faceting or cabochoning
3ct could be worth up to $3,000 If it stars could be worth a lot more.

Raw only about $100.00 - $200.00 *guessing

[marinedad]

could it be agate?

[Grace O'Malley]

I think it's a Yogo sapphire, judging by where it came from. How much would it cost to have this cut? How would you go about having it done?

[MRBeyer]

Grace, Love the avatar. You might want to contact Gem Mountain. They have a sapphire mine in Montana and are available on the internet. They gladly give out contact info in several gemcutters and appraisers. Their site also has interesting info on Sapphires.

http://gemmountainmt.com/default.aspx

[Goodyguy]

I think it's a Yogo sapphire, judging by where it came from. How much would it cost to have this cut? How would you go about having it done?

Any sapphire from the Yogo Gulch area is called a Yogo sapphire, however they are usually blue or violet.

[Grace O'Malley]

If it's not a sapphire, I don't know what it could be....do they ever find yellow diamonds in that area?

[Goodyguy]

If it's not a sapphire, I don't know what it could be....do they ever find yellow diamonds in that area?

I believe it's a sapphire, although I suggest you take it to a gemologist to have all your questions answered professionally.
Then let us know what you found out.

MRBeyer's idea of Gem Mountain in Philipsburg, Montana seemed like a good idea to me if it's not too far away.
Here is their info on faceting http://gemmountainmt.com/faceting.aspx

Otherwise take it to the nearest gemologist.

GG~

[Grace O'Malley]

Thanks for the link, MB. They have a lot of pics of raw sapphires.

[Eu_citzen]

Agate or quartz, pretty sure.
If it was sapphire the yellow colour would probably have trigonal colour zoning.

I do cabochon cut and facet as a hobby, but am located in Sweden. PM me with questions if you like.

If you'd like to keep it within the US contact gemsbyjennifer; http://www.gemsbyjennifer.com/
They have a lab to test it and a workshop to cut it. I know and trust them.

Overseas cutting (often Thailand, China etc) makes me sceptic.
Getting it cut in those countries is a gamble. Quality of the cut can be good or really, really bad. Mostly the later.

Ask anyone who does costume jobs and I bet you'd get the same answer!

I see a crack in there - use a small hammer and break it open, could give an important hint.
Either way it should yield at least 2 stones, can't cut one big due to the crack.

A steel knife just and just is softer then quartz I believe, 6.5 or so. So quartz should not get scratched.

As for worth - no idea but don't expect to get rich any time soon, lol.
Most of similar clarity (cabbing rough) is usually at say 10$/ carat and that often being with a star effect..
Without star it would be lower, and that are not wholesale prices.
10 grams is 50 carats.

Only the yellow colouring and/or locality could push it up a bit.

GG,
Don't mix up kt (Karat - used for gold alloys) and ct. (carat - 0.2 grams)

[Red_desert]

Thanks for the link, MB. They have a lot of pics of raw sapphires.

I watched a video recently from a gold prospector in Montana, showing a whole collection of sapphires from streams. They seem to be of all different colors and often look like a stream polished piece of glass.

[Goodyguy]

At any rate there is no real substitute for a first hand evaluation.
I would say that we have done all that can be expected simply from viewing your photos.

GG~



Thanks for the heads up, Eu_citzen
Being more of a geologist/gold prospector it was just a force of habit.

[Red_desert]

Tried finding the video, couldn't locate it. From what I remember, the sapphires looked really transparent, can't recall any with cracks or fractures either.

[Goodyguy]

Tried finding the video, couldn't locate it. From what I remember, the sapphires looked really transparent, can't recall any with cracks or fractures either.

Fractures, inclusions, color, clarity, etc. are what make the difference between specimen quality and gem quailty.
Her photos give the appearance of specimen only quality, but could simply be an illusion.