[meteorite-list] Ringwoodite

From: Mr EMan <mstreman53_at_meteoritecentral.com>
Date: Wed, 21 Jan 2009 19:41:33 -0800 (PST)
Message-ID: <98714.29485.qm_at_web55202.mail.re4.yahoo.com>

Hello Pete: Off the top of my head -- I don't recall ever hearing of "indigo" blue in a meteorite. I do know that ringwoodite is barely translucent with a pale purple-over-brown tint especially visible to the eye under a low power loupe. Perhaps it is just semantics.

When the list last visited ringwoodite veins, I believe they were almost always found in L chondrites but this could have been from paired finds. I say this suggesting that the bulk of ringwoodite veins observed/sampled on earth might have come from the same disrupted parent body-- but have nothing other than vignette evidence to support it.

I believe your discovery is about right regarding ringwoodite abundance. I have seen swellings of ringwoodite veins to about 3-5mm but 1mm is normal. Ringwoodite veins are likely injection veins along existing fractures/lines of weakness. The purity of the veins does not suggest the veins occur as flash melts.

About 8 years ago there was a run of ringwoodite bearing slices being sold but I believe it came from a larger find of multiple stones--Sorry I don't have the NWA numbers.

Please send a photo when /if you can.

Elton


--- On Wed, 1/21/09, Pete Pete <rsvp321 at hotmail.com> wrote:

> From: Pete Pete <rsvp321 at hotmail.com>
> Subject: [meteorite-list] Ringwoodite
> To: "meteoritelist meteoritelist" <meteorite-list at meteoritecentral.com>
> Date: Wednesday, January 21, 2009, 6:12 PM
> Greetings, all,
>
>
> In the experience of the chondrite-cutters, how common are
> you finding ringwoodite in shock melt veins?
>
> Personally, I've only seen (what I believe to be)
> ringwoodite in two stones out of the dozens I've cut.
>
> How about size? In mine, the largest area is ~ .5 mm.
>
> For such an outstanding indigo blue colour in a generally
> brown matrix, I'm surprised there isn't that much
> information about the mineral in meteorites on the internet
> or my books.
>
> Cheers,
> Pete
>
Received on Wed 21 Jan 2009 10:41:33 PM PST