Sabre52
Cave Dweller 
Me and my gal, Rosie
Member since August 2005
Posts: 20,504
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Post by Sabre52 on Dec 28, 2012 10:06:24 GMT -5
Howdy folks, Jan wanted to see pics of the chiastolite material collected up near our old ranch in Mariposa County , CA. This material came from a roadbed that cut through sort of a decomposing metamorphic micaceous shist deposit. The intact crystals ran about 3-4 inches long but in the process of being weathered from the matrix, they generally broke up into sections much smaller. Average crystal diameter at this site seems to be about 1/3 inch with any over 3/4 inch being uncommon. I think the black cross designs, which are different in different sections of the same crystal, are carbon inclusions. Made for a fun hunt anyway, kind of like hunting Easter eggs and the collecting site in the Sierra foothills, especially in the spring with all the wildflowers, was very pretty. Here are a few pics.......Mel Rough crystals dry. They always have a blackish carbon dust and the exteriors are covered in many cases, with tiny golden mica crystals.  Pictured wet to show cross patterns:  Little tumbled sections:  |
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Post by gingerkid on Dec 28, 2012 10:16:03 GMT -5
;D Thank you, Mel, for taking the time to post pics of your chiastolite finds! Wow, I'm amazed at how many you found, the size of the crystals, and love the tumbled ones!! Very nice cross patterns in them, too. Those are super!! Imagine the mica makes them sparkly?  |
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Post by deb193redux on Dec 28, 2012 10:36:19 GMT -5
it is a neat tumble
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Sabre52
Cave Dweller
Me and my gal, Rosie
Member since August 2005
Posts: 20,504
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Post by Sabre52 on Dec 28, 2012 10:40:17 GMT -5
Jan,
A buddy of mine from the Ventura Gem and Mineral Society, Greg Davis, makes cross themed jewelry from hand picked, matching, polished crystal sections. He donated a matching set Necklace, earrings etc to one of our Raptor Center silent auction fundraisers and it was a big hit and generated quite a little bidding war. Glad you guys reminded me of these as I've been wanting some filler to do with my turritella shells one of our members sent me and this stuff will be perfect....Mel
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Post by gingerkid on Dec 28, 2012 11:04:43 GMT -5
 Sure would've loved to have seen the jewelry pieces designed with chiastolite! Very nice cause, too!  Haven't seen many jewelry pieces designed with chiastolite before. Curious as to what you will create with the chiastolite and using the turritella (as filler?), Mel. 
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Sabre52
Cave Dweller
Me and my gal, Rosie
Member since August 2005
Posts: 20,504
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Post by Sabre52 on Dec 28, 2012 11:58:41 GMT -5
Jan: I don't do jewelry. I just use the chiastolite crystals as giveaways to the kids or grownups I take for nature walks. Folks are real religious around these parts and like cross rocks. The crystals don't take a fantastic polish, just sort of a high satin finish, but I'd think they'd make an interesting ring setting. They might shine up better with tin oxide. I only use optical cerium on my pads and AO in the tumbler. Tought I had a photo of Greg's creation in my photobucket albums but as yet have not found it. My albums are pretty huge *L*...Mel
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hand2mouthmining
spending too much on rocks
Purveyors of California Gem Rock
Member since September 2011
Posts: 495
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Post by hand2mouthmining on Jan 1, 2013 2:00:37 GMT -5
Mel, thanks for the great post on the Mariposa chiastolite! We had a fine trip out to Road 29 yesterday afternoon, with everyone finding good crystals without getting too wet. After the ground dries for a week or two, it'll be easier digging. I'll post a link to my chiastolite page in the Locations section.
Jan, I'm cabbing some of my new chiastolite this week, and will post photos to this thread as soon as possible. Should be up by Sunday, as I have a backlog from all my sick time.
Thanks!
Kris
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Post by gingerkid on Jan 1, 2013 8:34:39 GMT -5
Thanks, Kris! Looking forward to seeing your chiastolite cabs!  Will you be selling the cabs, and possibly whole xtls? I would love to have a cab and piece that has not been sliced. Would like to have some tumbled pieces, too! I have a semi-polished slice of chiastolite from Hunan China that I won from rocks2dust's auction sales. I'll have to remember to take a pic of it. Found this on GIA's website a couple of years ago. From what I gather, they heat-treated and resin-filled some chiastolite samples. The resin improved the clarity of the samples, but the heat-treatment did not improve the color much. (isn't the andalusite in the photo gorgeous?!) www.gia.edu/research-resources/gems-gemology/issues/summer2009-contents/summer2009-article4.html |
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hand2mouthmining
spending too much on rocks
Purveyors of California Gem Rock
Member since September 2011
Posts: 495
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Post by hand2mouthmining on Jan 2, 2013 14:06:07 GMT -5
Thanks, Kris! Looking forward to seeing your chiastolite cabs! Will you be selling the cabs, and possibly whole xtls? I would love to have a cab and piece that has not been sliced. Would like to have some tumbled pieces, too! I have a semi-polished slice of chiastolite from Hunan China that I won from rocks2dust's auction sales. I'll have to remember to take a pic of it. Found this on GIA's website a couple of years ago. From what I gather, they heat-treated and resin-filled some chiastolite samples. The resin improved the clarity of the samples, but the heat-treatment did not improve the color much. (isn't the andalusite in the photo gorgeous?!) www.gia.edu/research-resources/gems-gemology/issues/summer2009-contents/summer2009-article4.htmlJan, as soon as we get back in the shop, I'll post some cabs and rough for sale. My New Years Day was slept away with tummy flu ...  So I have to be patient, and recuperate.  Facet grade andalusite is lovely, and the resin idea is interesting. We're thinking of trying the water glass/Emergen-C treatment, less mess and toxic chemicals involved. Lots of potential there.  The alluvial/glacial till on Road 29 yields many different colors of chiastolite, brick red and peach being my favorites. We'll get the new water heater in our shop this week and get polishing! More soon! Kris |
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The Dad_Ohs
fully equipped rock polisher
Take me to your Labradorite!!
Member since September 2012
Posts: 1,860
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Post by The Dad_Ohs on Jan 2, 2013 14:14:58 GMT -5
Thanx for the posting Mel, my daughter was especially interested to see what the crystals looked like when raw, then wet, then tumbled. very cool !!
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Post by gingerkid on Jan 4, 2013 21:01:28 GMT -5
Kris, please don't treat your chiastolite xtls!! :nono: The one you posted is awesome au naturel!! Please let us know when you post them on your site, and hope you feel much better!! ;D |
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hand2mouthmining
spending too much on rocks
Purveyors of California Gem Rock
Member since September 2011
Posts: 495
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Post by hand2mouthmining on Jan 6, 2013 15:17:31 GMT -5
Jan,
Oh, no worries about treatments on un-cut chiastolite crystals! That would be marginally effective, and IMHO just wrong.
The treatment idea will be tried on cut cabs, before the final polish stage. Chiastolite is really soft, and wears best as a doublet or double sided triplet, with optical quartz. That increases the price to the consumer.
The treatment (hopefully) would lend hardness, making the stone more wearable without the time (cost) and trouble of a doublet.
Treatment is a "We'll see ...", and will have to show it's effects in experimentation.
In practice, the proposed treatment would just "agatize" the chiastolite, adding quartz for toughness. There should be little effect on the natural appearance.
We're having storms today, so it's a good day for photos. More later!
Kris
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Sure would've loved to have seen the jewelry pieces designed with chiastolite! Very nice cause, too! 
