Real Sapphire or Glass?

[aussiegems1984]

I am a little confused on how identifying a sapphire from glass with a gravity test?
I recently done a gravity test as shown in a link provided the gravity weight was totally different until i tared with empty paperclip.

It is now saying 4 as gravity weight but i also seen when researching gravity weights, that glass is the same? , is there any way i can work this out without wasting money getting testing in case it's glass?

It does have a chip concoidal fracture but read it depends on origin of where it came from? , Very stuck could somebody please help me out

[fossickeract]

Hi Aussiegems1984,
     If you have done your weighing and calculations accurately 4 is likely to be sapphire, common glass 2.2 to 2.5. Some speciality glass may be higher but not found commonly in creeks or jewellery. If  the stone is faceted a Refractive Index measurement at a local lapidary club would be better identification.
                                        Cheers Ted

[aussiegems1984]

Thanks Ted,

Could it still possibly be treated glass to make it fluoresce SW - greenish, LW - pinkish purple?
I think I'll also have to join up at a Lapidary club too

[fossickeract]

 Perhaps glass could be produced to fluoresce in this manner and some natural corundum may too, rubies  can but it doesn't indicate one or the other as far as I know, refractive index measurement is the only way!

[Aussie Sapphire]

Ted is correct that Refractive Index is going to help most in identifying - the beauty of the Specific Gravity test is that you can test rough stones - they do not need to be polished.

Specific Gravity test normally pretty reliable but if you were getting wildly varying readings, perhaps just a tiny bubble of air had attached itself to the stone - this can sometimes cause off readings.

Can see a reference chart for SG values here:
http://www.prettyrock.com/images/specificgravitychart.jpg
http://gemologyproject.com/wiki/index.php?title=Specific_Gravity

For some strange reason, the Gemology Project lists glass at 3.15 to 4.2 but most charts put glass down more at the 2.25 to 2.5 level.  It would be unusual to find glass measuring up at the 4.2 level but there are types such as lead crystal glass that are very dense.

Fluorescence   No clue.

cheers
Leah

[jasonr]

Hi Aussiegems ....

No disrespect intended but you have been banging on about this little blue stone on this forum and others for weeks now.

Many people have given you suggestions on what to do, yet nothing seems to be getting you any closer to identifying it.
Time perhaps to make a decision

1. Put it on the shelf and call it "my little blue mystery"
2. Try to melt it.  Glass - app 1500c Sapphire - app 2030c   
3. Do what most people have suggested and take it to a professional.

I do applaud initiative and figuring stuff out for yourself however one also needs to draw a line and accept defeat when that appears to be the case.

SG tests will be hit and miss with the home made test due to various factors and the closeness of glass and sapphires SG.

It may also benefit you to know that mohs scale puts Sapphire at a hardness of 9. Glass is around 6-7
http://www.amfed.org/t_mohs.htm

I would imagine most jewellers and lap clubs would have a device to test hardness.
However in your very first post you said that you scratched the "stone" with a piece of Quartz ..... that wouldn't have happened with a Sapphire.

I think you have found a beach that was very popular last century, hence the pennies everywhere.
Would people of that period worn valuable Rubies and Sapphires to the beach not likely.
Coloured glass jewellery ... more likely.

Did you end up taking a metal detector back there ?
If so, anything thing else interesting turn up.

Best of luck .... or take it to someone who knows what they are doing when it comes to mineral identification.

Regards
J

[Aussie Sapphire]

No disrespect intended but you have been banging on about this little blue stone on this forum and others for weeks now.
Many people have given you suggestions on what to do, yet nothing seems to be getting you any closer to identifying it.

I have seen this type of situation before when the suggestions dont fit with what the OP is hoping the stone might be ;-)

Yes - if the DIY options are not working and it is important to you to get the ID, then just take it to a qualified gemmologist.  If it is just for fun, then leave it in the "unknown" pile.

Discussing this kind of stuff on forums (here and elsewhere) is fun but really just uninformed opinion because none of us have the stone in front of us.  Just impossible to ID from photos - best you can hope for is some advice to point you in the right direction.

Hardness tests can be useful where there is quite a big difference - as might be in this case between glass and sapphire - but it is a destructive test and so not suitable for some situations.  However, if the stone is already pretty rough from tumbling round at the beach, then a tiny little scratch in an unobstrusive spot might just narrow it down - if a piece of topaz or garnet will scratch it, then you know it is very unlikely to be sapphire. 

However, you may be ignoring other possibilities - just take it to a gemmo and get an expert opinion. If you do not need a written report, a verbal inspection and ID can be quite affordable.

cheers
Leah

[jasonr]

Oh yes Leah, I think the OP really really wants this to be a Sapphire
As would we all ...

Imagine that ... a beach with Sapphires, Rubies, and coins. Seemingly untouched by others as these items were easily "specced" on the surface.
In QLD nonetheless

Aussiegems, I personally would put it on the shelf as a mystery piece to be talked about for years to come.

If you really want a Sapphire then myself and many others here would happily take you to places where you will definitely find one

Sincerely
Jason R

[aussiegems1984]

Hi Aussiegems ....

No disrespect intended but you have been banging on about this little blue stone on this forum and others for weeks now.

Many people have given you suggestions on what to do, yet nothing seems to be getting you any closer to identifying it.
Time perhaps to make a decision

1. Put it on the shelf and call it "my little blue mystery"
2. Try to melt it.  Glass - app 1500c Sapphire - app 2030c   
3. Do what most people have suggested and take it to a professional.

I do applaud initiative and figuring stuff out for yourself however one also needs to draw a line and accept defeat when that appears to be the case.

SG tests will be hit and miss with the home made test due to various factors and the closeness of glass and sapphires SG.

It may also benefit you to know that mohs scale puts Sapphire at a hardness of 9. Glass is around 6-7
http://www.amfed.org/t_mohs.htm

I would imagine most jewellers and lap clubs would have a device to test hardness.
However in your very first post you said that you scratched the "stone" with a piece of Quartz ..... that wouldn't have happened with a Sapphire.

I think you have found a beach that was very popular last century, hence the pennies everywhere.
Would people of that period worn valuable Rubies and Sapphires to the beach not likely.
Coloured glass jewellery ... more likely.

Did you end up taking a metal detector back there ?
If so, anything thing else interesting turn up.

Best of luck .... or take it to someone who knows what they are doing when it comes to mineral identification.

Regards
J

Thanks Jason for your thoughts,

No I haven't hired a metal detector yet. I also haven't tested stone yet as im not made of money and there is easier ways! that's why I said I,m joining up at a lapidary round the corner!.
I have scratched with a very sharp piece of what looks like spiky sharp quartz crystals ( I think they would scratch anything faceted gem as i've read)

The red stone I found is 2.56 which Im guessing red glass THIS is why I am more interested in blue stone.
I don't put things aside until I know what I'm looking at.
 And this forum is opened to suggestions that's why I use it

Cheers

[aussiegems1984]

No disrespect intended but you have been banging on about this little blue stone on this forum and others for weeks now.
Many people have given you suggestions on what to do, yet nothing seems to be getting you any closer to identifying it.

I have seen this type of situation before when the suggestions dont fit with what the OP is hoping the stone might be ;-)

Yes - if the DIY options are not working and it is important to you to get the ID, then just take it to a qualified gemmologist.  If it is just for fun, then leave it in the "unknown" pile.

Discussing this kind of stuff on forums (here and elsewhere) is fun but really just uninformed opinion because none of us have the stone in front of us.  Just impossible to ID from photos - best you can hope for is some advice to point you in the right direction.

Hardness tests can be useful where there is quite a big difference - as might be in this case between glass and sapphire - but it is a destructive test and so not suitable for some situations.  However, if the stone is already pretty rough from tumbling round at the beach, then a tiny little scratch in an unobstrusive spot might just narrow it down - if a piece of topaz or garnet will scratch it, then you know it is very unlikely to be sapphire. 

However, you may be ignoring other possibilities - just take it to a gemmo and get an expert opinion. If you do not need a written report, a verbal inspection and ID can be quite affordable.

cheers
Leah

Thanks Leah,

Would you know of any jewellery stores that do that sort of identification without sending away?

Jessie

[Aussie Sapphire]

I have scratched with a very sharp piece of what looks like spiky sharp quartz crystals ( I think they would scratch anything faceted gem as i've read)

Scratch tests are the least useful of the gemmological tests although they have their place to assist with an ID.  However, you DO need to know exactly what you are scratching with or you could be comparing to the wrong hardness level.  "Looks like" quartz might be quartz or it might be something else entirely.

If you are getting a scratch with quartz, that is only distinguishing anything below 7 - ie. glass or opal type hardness.  It is not necessarily ruling out anything 7 and above which includes a lot of the faceted gems out there.

It is not difficult to put together a home made scratch test kit but you really need to be sure that the reference minerals are what they should be - they dont have to be great examples but they do need to be accurate.  For example, opaque corundum is cheap as chips or can be found relatively easily so you dont need a gem quality sapphire or ruby for your 9 reference mineral.

cheers
Leah

[Aussie Sapphire]

Would you know of any jewellery stores that do that sort of identification without sending away?

Just about all of them wont.  Jewellery stores now tend to be just places where they buy in stuff and sell it.  You need to look for a gemmologist - some of the high end jewellers who actually do a bit of bench work and/or manufacturing may have one on staff but it is extremely unlikely for your standard high street chain store jeweller.

Suggest you contact the GAA for help on someone nearby to you
http://www.gem.org.au/

Alternatively go to your nearest gem show - quite often they will have someone (or one of the dealers) who can offer this service on the day.

cheers
Leah

[aussiegems1984]

Would you know of any jewellery stores that do that sort of identification without sending away?

Just about all of them wont.  Jewellery stores now tend to be just places where they buy in stuff and sell it.  You need to look for a gemmologist - some of the high end jewellers who actually do a bit of bench work and/or manufacturing may have one on staff but it is extremely unlikely for your standard high street chain store jeweller.

Suggest you contact the GAA for help on someone nearby to you



http://www.gem.org.au/

Alternatively go to your nearest gem show - quite often they will have someone (or one of the dealers) who can offer this service on the day.

cheers
Leah

Thanks this great help

[scratchie]

I think you've been given the best advice in this forum. Take it to a qualified gemmologist who will give you a written identification . All your wonderings will be over .
And also not all lapidary clubs will have a member who is a QUALIFIED gemmologist. Don't take the word of any average rockhound - get a 100% identification and put the matter to rest.
Good luck
John

[jasonr]

Whereabouts in QLD are you Aussiegems ? ? ?