⭐ Gemstone & Mineral Show n Tell
- Thread starter Colin&Lee
- Start date
Help Support Prospecting Australia:
Most likely Spinel of some sort. There are quite a few different stones in the Spinel group, is it attracted to a magnet? Some are attracted to magnets such as Magnetite.
Jumps across the room at the wave of a magnet .. so is that a positive for magnetite or just a possibility ? Never seen it before looks nothing like what i thought spinel was
Most likely 5ft, still a possibility I'm not 100% on what it is as there are quite a few types of Iron Spinels. The Spinel from say Grabben Gullen is the typical Black Spinel which is a fantastic jet black gemstone which is Magnesium Aluminium Oxide MgAl2O4, looks awesome cut and polished, is non-magnetic. A lot of the Spinel from Nth NSW I've seen is very silvery looking and very magnetic, I've got some here from BB.
Check the link as it's not a bad read on the subject.
https://en.wikipedia.org/wiki/Spinel_group
Check the link as it's not a bad read on the subject.
https://en.wikipedia.org/wiki/Spinel_group
5ftfossicker said:
Nice.
Yeah me too mate, but a lot of the geology and chemistry associated with minerals can be pretty advanced stuff, a lot of it leaves me dazed and confused.....
Yeah , that link reminds me why i zoned out in school. Thanks though, not sure it is magnetite as apparently magnetites brown in sunlight, this is very metallic, pewter or silver looking
But it leaves black streak test .. yep im just going to call it spinel
Magnetite will leave a black streak. Black Spinel leaves no streak......
Just had to make it more confusing didnt you.
From what i have read this arvo richo, it changes a lot depending on where in the country you are ? Eg , tasmanian spinel, will look different to victorian spinel , and again different up at inverell to further northern nsw and so on
Doesnt make sense to me but im a bit simple i guess
5ftfossicker said:
Yup!
Sodabowski
Thomas Rodriguez
Nice score, whatever it is. The druzy quartz stalactite is a beauty!
- Joined
- May 1, 2014
- Messages
- 1,958
- Reaction score
- 2,530
Heatho said:
Black spinel certainly does make a very fine looking faceted stone. The fact it isn't transparent doesn't matter, I did a piece a while ago in checker cushion cut, didn't bother doing a pavilion as it can just sit down in a deep bezel. The stuff takes on a brilliant polish and looks particularly good in a blokes ring. Got a good hardness so it's pretty scratch resistant.
I think more use should be made of it
5ft - is that obsidian on the previous page?
- Joined
- May 16, 2013
- Messages
- 489
- Reaction score
- 660
That is just beautiful KS.
Mackka
Mackka
Similar threads
