[meteorite-list] NWA 1685 or Dean's BL

From: bernd.pauli_at_paulinet.de <bernd.pauli_at_meteoritecentral.com>
Date: Thu Apr 22 10:31:14 2004
Message-ID: <DIIE.0000003100001FB4_at_paulinet.de>

Hello Dean, BL-owners and List,

Today I took some digital pictures of several of my thin sections
under crossed polarized light. Among these, my NWA 1685 thin
section which I purchased from Dean a few days ago and I am
glad I did. He had another one on EBay but I've just bought it with
"Buy It Now" :-)

The BL's have already been the subject of much debate and whatever
they will finally be classified as, they are beautiful, they are extraordinary.
There are now two gorgeous, cut specimens in my collection: 131 grams
and 251.3 grams with fantastic fusion crust and regmaglypts - plus these
two thin sections.

Here is what I found in the BL thin section thaI I already own:

Both in hand specimen as in thin section there are areas that are absolutely
featureless, devoid of any chondrules or other inclusions, and look almost
achondritic.

The view under crossed polars is breathtaking: While there are chondrules
and mineral components of various sizes in a fine-grained, almost opaque
groundmass, the featureless clast in my TS shows an incredible, equigranular
structure without any fine-grained, interstitial groundmass ... as if it had been
"blown" or "swept" away.

Never before have I seen this in any other thin section that I have or that I
have seen pictured in the literature. Imagine hundreds and hundreds of
colorful little pearls seen from a distance.

Best wishes,

Bernd
Received on Sat 17 Apr 2004 03:27:46 PM PDT