Blue Asbestos

I have recently purchased an old rock and mineral collection. Amongst this are several specimens of Blue Asbestos on Matrix, all hand specimen size or bigger. Suspect it comes from Australia. Because it is fibrous and hazardous, I have rewrapped it and sealed the specimens in pastic bags. How dangerous is this stuff on matrix ... or should I simply dispose of it?

Also, I have several specimens of Black tigers eye from Sth Africa which the fibres have parted and come loose on. I take it this too can be hazardous?

Thanks in advance.

Chris. J

Hello,

It's riebeckite asbestos, a really dangerous stuff. I have a sample from Australia, too. It's in a plastic box. Wrapped in a plastic box it isn't harmful, but don't open the box again. If you don't want the specimen then swap or sell it. This blue asbestos leads to some severe forms of lung cancer, including the deadly mesothelioma. It's more dangerous than serpentine asbestos like chrysotile.

The location in Australia is called Wittenoom Gorge (don't know if it is written right).

Regards,

Sebastian Möller

If you wanted to keep the stones, you can seal them with a pva/water solution so that the fibres are bound to the bulk sample and as a result, the fibres are unable to be inhaled or respired. If you disturb the rocks however, the potential for fibre release will increase. I suggest the same, either seal the specimens, or dispose of them accordingly. And yes, the Black tigers eye is also a hazardous substance.

Kevin

Allow me to add a word of caution. Yes, Asbestos - asbestiform riebeckitic amphibole a.k.a. Crocidolite and others - is a potential health problem but you do have to breathe the dust to be exposed to danger. In all likelihood you will even have to breathe it often for an extended period of time.

No, I can not guarantee you have not already been exposed to a fatal dose. Just as well as I can not exclude you will develop lung cancer from the second-hand smoke you were exposed to from somebody standing outside a bar [I am allergic to tobacco smoke and notice this is a rather vivid way]. But in all likelihood, a minimal exposure - such as gently handling a mineral specimen - will not be hazardous, much less fatal.

Chris, I am not quite sure what you mean, when you say 'black tigerseye'.
'Blue tigerseye' a.k.a. 'falcons eye' is a silicified asbestiform riebeckitic amphibole. Given it is silicified, I doubt it will be a source of hazardous, airborne fibres. When cut, it will produce silica dust, which may be a serious hazard (this also applies to Amethyst, Rose Quartz, ...).
'Golden tigerseye' does not contain any asbestos but is a weird growth form of Quartz (there was a paper on this in American Mineralogist 3-4 years ago or so - I can find it if it is essential). As such it will represent no other dangers than an Agate/sandstone, except if cut.

All the best

Claus

____________________________________________________________________________
Claus Hedegaard
[www.Hedegaard.com]
Strandvejen 2a, 8410 Rønde, Denmark

"Chris, I am not quite sure what you mean, when you say 'black tigerseye'.
'Blue tigerseye' a.k.a. 'falcons eye' is a silicified asbestiform riebeckitic amphibole. Given it is silicified, I doubt it will be a source of hazardous, airborne fibres. When cut, it will produce silica dust, which may be a serious hazard (this also applies to Amethyst, Rose Quartz, ...).
'Golden tigerseye' does not contain any asbestos but is a weird growth form of Quartz (there was a paper on this in American Mineralogist 3-4 years ago or so - I can find it if it is essential). As such it will represent no other dangers than an Agate/sandstone, except if cut. "

Heya Claus,

What happens when you have golden and blue tigereye in the same specimen?

Plus, what are the fiborus things that are on some of the golden tigereye? I'v got some speicmens that are only mostly silicated, with some fibers of riebeckite hanging off. Or, is that just a weird quartz growth?

I personally think that stuff is all across the spectrum, from Asbestos free golden tigereye, to silicated Riebeckite, in both golden and blue. Sometimes it is so dark it is black. Sometimes it is a bit brown.

The precursor material of both colours of Tiger Eye is fibrous riebeckite. The indurated varieties are pseudomorphs, in which the riebeckite may be silicified without altering its colour, or oxidised &/or indurated with iron oxide as well as silica, giving rise to the gold form. Hence, whilst some specimens may be totally silicified, if the alteration is incomplete, it is quite possible for some material to show both colours in the same piece, and some may contain residual asbestiform riebeckite.

I know there is no way of telling/quantifying exactly what is a "totally safe" way of handling asbestiform specimens, but there is a common sense path. Most people who have suffered mesothelioma due to riebeckite asbestos are those who have been exposed to much higher concentrations of the dust for much longer periods than any mineral collector. e.g. mine workers in areas where the material is found, or those working in plants manufacturing asbestos products.

I received my first specimen of asbestiform riebeckite as one of a set of local minerals sent to me for my birthday by my father when he was working in Rhodesia. It is a loose crumbly piece with exteremely fine silky fibres, and it was in an open tray. I have handled it on several occasions, although I have avoided doing so in draughty conditions, so as to minimise the dispersal of any dust from it, and I am still here and breathing well. (I say "Rhodesia" because that is what Zimbabwe was called when my father sent me the specimen, over 40 years ago).

So my procedure for handling asbestiform minerals is caution, yes, paranoia, NO! Treatment such as sealing them in resin or glue, or coating them in varnish reduces them to being simply pretty pebbles, not scientifically useful mineral specimens. I would say if you are that worried about the hazards, just don't keep any asbestos specimens.

If you do keep asbestos minerals, it is probably best to keep them in a self-seal plastic bag or a box with a lid, and take measures to avoid breathing the dust when you have reason to take them out (for microscopy etc), but they won't do any harm unless fibre particles are inhaled, and they're not going to chase you around the room and fly at you like the alien larvae that got at John Hurt!

Pete N.

Hello all,

The paper that Justin was referring to about the new theory of Tiger eye was written by Peter Heaney and Donald Fisher at Penn State. The new theory states that golden Tiger eye contains both weird column shaped quartz crystals and fibers of crocidolite crystals. Since the quartz formed in distinct column shaped crystals , the researchers concluded that golden Tiger's eye was not a pseudomorph (xls too uniform), but formed by a "crack-seal" mechanism. They further concluded that the chatoyancy was due to the included crocidolite, and not the quartz.

Jen

The reference (one of many locations for the theory - probably in AM too):
Heaney, P.J. and Fisher, D.M. (2003) A new interpretation of the origin of tiger’s-eye. Geology, 31, 323-326.



Edited 1 time(s). Last edit at 05/14/2008 05:36PM by Jennifer Nemitz.

I'd just like to say thanks to all for the replies, appreciated.

I have both the golden and black coloured Tiger's Eye from Sth Africa - often the black (or blue-black) comes in the same rock as the gold, and in this case I also have pieces which consist of black only. Have seen it sold as Falcoln's Eye. The fibres in this have comes loose and are just like asbestos. I think for my specimens, I'll apply the common sense method. I've also seen other people's specimens which have been cut and the ends parted into individual fibres. Perhaps not completely silicified?

Chris. J