ID Help - gemstone?

[izak_]

Hello!

 

This is just a little stone we found near Tambar Springs in NSW Australia. It was on the bottom of a creek bed in gravel. The creek was on flood planes surrounded by hills, I believe granite(?)

I'm no expert on this stuff, so if you need any more info just let me know. Its probably not anything. At first I thought it was just quartz, but I don't remember seeing any other quartz in the area. maybe calcite? no idea

btw it weighs 0.0330 oz if that helps at all

[ynot]

You need to test the hardness (mohs scale) to be able to see what it is.

Possibilities- Quartz, Calcite, Fluorite, feldspar....

[dmbozeman]

It looks like quartz to me. I have several examples that look exactly like this.

[ynot]

5 minutes ago, dmbozeman said:

It looks like quartz to me. I have several examples that look exactly like this.

The piece in question appears to have 4 sides while quartz has 6 sides.

It maybe quartz, but without further information it is impossible to be sure.

[izak_]

4 minutes ago, ynot said:

The piece in question appears to have 4 sides while quartz has 6 sides.

Just want to say, this is a piece of the original crystal tha has broken off, you can see fracture marks in person.

[ynot]

1 minute ago, Foozil said:

you can see fracture marks in person.

What are the shape of said fractures?

[izak_]

10 minutes ago, ynot said:

What are the shape of said fractures?

I can't really explain very well. on each face, there are bumps and voids, often circular in shape. None of the faces are the same. It looks pretty recently broken, because the fractures are often still kinda sharp.

Also, there are hairline cracks in the stone with dirt inside, thats what the red-ish colour is.

Looking closely at the above photos you can almost see what i'm talking about

[Chase_E]

Hard to tell without further testing of the rock, but to me it's probably a piece of quartz. It could also be topaz, but that's highly unlikely.  It does look like some of the topaz that I own, but I'm unsure as to my topaz's locality. 

[ynot]

Need a hardness test to determine what it is.

[Macrophyseter]

Although if you really want to dive down on the exact, then youd have to perform many tests, and as ynot said, a hardness test would be it.

 

But my guess is that its just quartz, although ynot's other candidates are possible, but they are probably very rare.

 

So what we know is that it has a vitreous luster and glassy cut textures.

[ynot]

2 minutes ago, Macrophyseter said:

but they are probably very rare.

All four are very common minerals that can be clear and have inclusions (mud filled crack).

[izak_]

8 minutes ago, ynot said:

Need a hardness test to determine what it is.

From this website (http://www.rocksandminerals.com/hardness/mohs.htm), I have determined this rock is over "5". I don't know what tools I can use next, so I'll do some research

[Macrophyseter]

Just now, ynot said:

All four are very common minerals that can be clear and have inclusions (mud filled crack).

Yes, they are all very common, but I find the candidates other than quartz in a crystal condition like that (vitreous luster and glassy cut texture) found in a creek to be rare. I'm pretty sure that those types would usually be found in caves or deep underground.

[ynot]

1 minute ago, Foozil said:

I have determined this rock is over "5".

That rules out fluorite and calcite.

[izak_]

using a knife (as recommended by the website) there was a very slight but visible scratch. It is tiny though

[Macrophyseter]

6 minutes ago, Foozil said:

From this website (http://www.rocksandminerals.com/hardness/mohs.htm), I have determined this rock is over "5". I don't know what tools I can use next, so I'll do some research

Ive heard that feldspar is the most common mineral on earth, but since then youd have to test THAT to certify, I can suggest using granite. Granite is mostly feldspar and quartz, and every other lesser mineral in there in softer than both, so you can just assume it as either quartz or feldspar.

[izak_]

Granite made a very very slight scratch, about the same as the knife.

[ynot]

4 minutes ago, Macrophyseter said:

found in a creek to be rare. I'm pretty sure that those types would usually be found in caves or deep underground.

Most anything found underground can be found on the surface. Erosion does that.

 

 

3 minutes ago, Foozil said:

using a knife (as recommended by the website) there was a very slight but visible scratch. It is tiny though

Make sure it is a scratch and not a streak left by the knife.

If it is a scratch then it is most likely a feldspar.

 

2 minutes ago, Foozil said:

Granite made a very very slight scratch, about the same as the knife.

granite is made from several minerals and should not be used as a test item because You can not be sure which mineral is making the scratch.

[izak_]

1 minute ago, ynot said:

Make sure it is a scratch and not a streak left by the knife.

You're right, the scratch just rubbed off.

 

Could this be glass? The best way to describe this stone is like glass, are there any other minerals that behave like glass?

And thanks for all your help, everyone.

[ynot]

5 minutes ago, Foozil said:

You're right, the scratch just rubbed off.

Quartz if the knife did not scratch it.

[izak_]

Just now, ynot said:

Quartz if the knife did not scratch it.

Thank you!

[Sagebrush Steve]

On 7/24/2017 at 8:52 PM, Foozil said:

Hello!

 

This is just a little stone we found near Tambar Springs in NSW Australia. It was on the bottom of a creek bed in gravel. The creek was on flood planes surrounded by hills, I believe granite(?)

I'm no expert on this stuff, so if you need any more info just let me know. Its probably not anything. At first I thought it was just quartz, but I don't remember seeing any other quartz in the area. maybe calcite? no idea

btw it weighs 0.0330 oz if that helps at all

 

My go-to test for these kinds of questions is to measure the specimen's specific gravity.  Since you already know how much it weighs in air, you must have access to a good scale. Now all you need to do is measure its weight in water.   Here is a link to one way to do this: specific gravity.  If it is quartz its specific gravity will be about 2.65.  If it is different from that, post the number you calculate and we can give you some ideas.  I like specific gravity as a more definitive test than the scratch test because the scratch test only tells you whether the specimen is harder or softer than your knife, not exactly how hard it is.  Specific gravity will weed out a lot more possibilities.  And to regular readers of this forum, sorry I sound like a broken record, I've been advocating the specific gravity test a lot lately. It's really good, but of course you need to make sure your specimen isn't something that will dissolve in water!

[Sagebrush Steve]

On ‎7‎/‎24‎/‎2017 at 9:19 PM, Sagebrush Steve said:

My go-to test for these kinds of questions is to measure the specimen's specific gravity.  Since you already know how much it weighs in air, you must have access to a good scale. Now all you need to do is measure its weight in water.   Here is a link to one way to do this: specific gravity.  If it is quartz its specific gravity will be about 2.65.  If it is different from that, post the number you calculate and we can give you some ideas.  I like specific gravity as a more definitive test than the scratch test because the scratch test only tells you whether the specimen is harder or softer than your knife, not exactly how hard it is.  Specific gravity will weed out a lot more possibilities.  And to regular readers of this forum, sorry I sound like a broken record, I've been advocating the specific gravity test a lot lately. It's really good, but of course you need to make sure your specimen isn't something that will dissolve in water!

For those of you who may be interested in knowing the specific gravity of common gemstone materials, here is a table I compiled from published sources: Specific Gravity of Common Stones.pdf.