Naked Science Forum

Non Life Sciences => Geology, Palaeontology & Archaeology => Topic started by: ZekemanGerb on 12/04/2013 20:25:45

Title: What is this iridescent, colourful mineral?
Post by: ZekemanGerb on 12/04/2013 20:25:45

I got this as a gift. But i do not know what it is. Help me maybe? (https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FQIFa5b7.jpg&hash=21913986833cf2db8213fa0f6d22a02d)               (https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2F2gLDNuy.jpg&hash=90c031121ce96a0815ed8cd4c78112e6)                    (https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FpMTu071.jpg&hash=af9378f3ad5577e457f2cf547dcf26a1)

Title: Re: Help with identification
Post by: RD on 12/04/2013 20:45:03

 [ Invalid Attachment ]

Reminded me of iridescent "ChromaFlair" paint ... https://en.wikipedia.org/wiki/ChromaFlair


Peacock ore ? ...

(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fgwydir.demon.co.uk%2Fjo%2Fminerals%2Fpix%2Fpeacock3.jpg&hash=678cb055308dc578affd2bdc9d26bf2d)
http://gwydir.demon.co.uk/jo/minerals/peacock.htm

Title: Re: Help with identification
Post by: ZekemanGerb on 12/04/2013 20:50:47

Well i know this is a chromaflair geode, (https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2Fe4qKDEF.jpg&hash=e8782d4c2ed484d0077cc0486b134119)    But the black one is really shiny and only a small part is multicolored

Title: Re: Help with identification
Post by: ZekemanGerb on 12/04/2013 20:55:04

But it does look like bornite

Title: Re: Help with identification
Post by: Bill S on 12/04/2013 23:16:02

Bornite is a good starting point, but based on the pictures, the tarnish is not as extensive as one might expect.  Also, the untarnished colour of bornite tends to be more reddish/brown. 

Chalcosite is another possibility.  Perhaps try to obtain a streak.  Bornite tends to give a lighter streak.  OK, that's not going to be a lot of help unless you have specimens of both to make a comparison. :)

Try scratching it. If you are unable to make any impression on it with a knife let us know and we may be able to think of some more suggestions, but at least that would rule out bornite and chalcosite.

Title: Re: What is this iridescent, colourful mineral?
Post by: cheryl j on 02/06/2013 22:24:28

I don't know but I think have the same rock.

Title: Re: What is this iridescent, colourful mineral?
Post by: JRajotte on 07/06/2013 04:14:50

This definitely looks like bornite.

Title: Re: What is this iridescent, colourful mineral?
Post by: Bass on 07/06/2013 16:09:49

Bornite has very poor cleavage- this specimen shows good cleavage.  I suspect your specimen is showing pleochroism due to oxidation from weathering.  I've seen this in pyrrhotite, pyrite, specular hematite, stibnite and other metallic minerals.
How hard is the specimen?

Title: Re: What is this iridescent, colourful mineral?
Post by: cheryl j on 09/06/2013 00:54:05

 It is hard and brittle, with a rough bark-like surface. Flakes of it will come off, the way mica does. It has a bit of every colour in it- purple, pink, gold, blue, green, etc.

Title: Re: What is this iridescent, colourful mineral?
Post by: Bass on 09/06/2013 01:35:31

is it magnetic?  even weakly magnetic (hold the magnet by a string and see if it moves at all near the specimen)?

Title: Re: What is this iridescent, colourful mineral?
Post by: cheryl j on 09/06/2013 14:01:12

No, it doesn't appear to be.

Title: Re: What is this iridescent, colourful mineral?
Post by: Bill S on 03/08/2013 02:38:50

Quote from: Cheryl

Flakes of it will come off, the way mica does.

You could have solved it, there, Cheryl!  It could be micaceous hematite. 

Any luck with the streak? If you can't scratch it with anything else, try a piece of quartz.  If the streak is red, micaceous hematite is a fairly good bet.