A very large faceted mineral/gem, uncertain as to what it may be

[fredflintstone]

Mini update:
I had an experienced geologist take a look at it and we did some very rudimentary tests. What emerged conclusively was that it isn't glass (we scratched a pane of glass with it).

So that was fun and reassuring for what it's worth.

She told me to have a gemologist look at it, but I haven't found any locally so I will have it examined at a lab when I next get to go abroad. Whatever it is (Beryl? Tourmaline? Something else?), I can drop some/a rupees/bag of salt on having it analized properly (unless it makes no sense financially but is shouldn't be too expensive?)

Didn't take the time to read through the whole thread.

Glass will scratch glass, so that method is out in determining what you have, glass or a gemstone. See if it will scratch quartz, as quartz is 7 hardness and common and cheap. Also, glass is warmer to the touch than gemstones due to its amorphous structure. The lip test which feels colder is a good indicator of glass verses gemstone.

Now, though Tourmaline has been known to come in moderately large sizes, beryl, especially Aquamarine can come in mind boggling size. With that in mind if this is a real gemstone, I'd have to say it was a beryl, of the Aqua sort.

 

[Headintheclouds]

Didn't take the time to read through the whole thread.

Glass will scratch glass, so that method is out in determining what you have, glass or a gemstone. See if it will scratch quartz, as quartz is 7 hardness and common and cheap. Also, glass is warmer to the touch than gemstones due to its amorphous structure. The lip test which feels colder is a good indicator of glass verses gemstone.

Now, though Tourmaline has been known to come in moderately large sizes, beryl, especially Aquamarine can come in mind boggling size. With that in mind if this is a real gemstone, I'd have to say it was a beryl, of the Aqua sort.

Thanks for your recomendations
I scratched some quarz with it just now. Was a little intense.

If it is Beryl, the colour seems a bit off for it to be aquamarine I think, and maybe it has too many inclusions even if they are minute (flakes they seem to be, maybe mica or other cilicate).

Anyway, the next step will be definitive.
Surely.

 

[fredflintstone]

Thanks for your recomendations
I scratched some quarz with it just now. Was a little intense.

If it is Beryl, the colour seems a bit off for it to be aquamarine I think, and maybe it has too many inclusions even if they are minute (flakes they seem to be, maybe mica or other cilicate).

Anyway, the next step will be definitive.
Surely.

Unheated Aqua is often that color saturation in large stones. The stone is huge, so inclusions are normal for a stone that size. They heat Aqua in most cases to burn off the green and leave the blue. The stone being so large the color will be deeper in Aqua, again deeper saturation.

No, I think you have an Aqua here. It has all the earmarks of Aquamarine.

But take it to a gemologist, as you said. Very easy to identify.

 

[Headintheclouds]

Unheated Aqua is often that color. The stone is huge, so inclusions are normal for a stone that size. They heat Aqua in most cases to burn off the green and leave the blue.

No, I think you have an Aqua here. It has all the earmarks of Aquamarine.

But take it to a gemologist, as you said. Very easy to identify.

Excellent, will do. Will be happy in any case

 

[Headintheclouds]

One question I do have regards the apparent narrow colour zoning. Those brownish stripes are few and whilst not directly on the surface, are close to it and don't dig deep.
Found some very interesting things online regarding zoning although I did not understand much of it, but it is engaging.

I'm sure aquamarine has all type of pecularity and singularities, I just haven't seen this type of phenomenon occur, but it doesn't mean much in itself.

 

[PrecisionGem]

Why don't you pick up a refractometer? I see you can get some pretty inexpensive ones on Amazon for less than $100. You can quickly rule out what it isn't with this one tool.

 

[Headintheclouds]

Will look into it