Zoran
freely admits to licking rocks
Member since September 2005
Posts: 880
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Post by Zoran on Sept 21, 2006 16:23:27 GMT -5
Finally, after long period I get some time to make some cabs. First three are made from rocks that I got at Budapest rock fair, this August, and next three are Serbian rocks - from my latest rock trip.  Malachite (20mm cab) from Kongo (Zaire).  Hawk eye (20x16mm cab)  Labradorite (20x16mm cab)  "Under the sea" Letze jasper (40x24mm)  Could this be some kind of plume - Also from Letze area (44x15mm)  Letze lace agate (38.5x18.5mm) Thanks for looking. Zotika |
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Sabre52
Cave Dweller 
Me and my gal, Rosie
Member since August 2005
Posts: 20,494
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Post by Sabre52 on Sept 21, 2006 17:06:13 GMT -5
Awesome work Zotica! Especially like the letze jasper. It does look kinda plumey. On another topic, we were having a discussion on how the orbicular ( poppy) type jaspers form. I think you're our only working geologist and you definately have some nice poppy stuff in your neck of the woods. Have you heard an explanation you agree with on the formation of these specimens?...mel
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Post by stoner on Sept 21, 2006 17:21:18 GMT -5
Very nice Zotika. Glad you had some time to cut some cabs. I think my favorite is the under the sea one. Are you doing the silversmithing now too?
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Post by gemkoi on Sept 21, 2006 20:25:53 GMT -5
I agree, very nice lot, all of them but my fav is the under the sea one. Got a purple color to it. Thanks for sharing Z~
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Post by krazydiamond on Sept 21, 2006 20:26:36 GMT -5
great works, Zotika, love the shapes. and the drill holes so close to the edge!!!!! nerves of steel.
hope your part of the planet is holding together, cheers,
KD
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WyckedWyre
fully equipped rock polisher
Member since April 2007
Posts: 1,391
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Post by WyckedWyre on Sept 21, 2006 21:00:31 GMT -5
Love the Letze from the Octopus's Garden (Under The Sea).
;DS
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Post by sandsman1 on Sept 21, 2006 23:41:46 GMT -5
lookin good zot i realy like that first one but there all A+ work ---hey i tried drillin your way and i gotta say i like it better then the drill press i get better holes and it goes faster thanks for the tip
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Post by Tweetiepy on Sept 22, 2006 7:46:20 GMT -5
I really like those! - that labradorite is awesome and the first green one is amazing...
Great job!
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stefan
Cave Dweller
Member since January 2005
Posts: 14,113
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Post by stefan on Sept 22, 2006 9:36:21 GMT -5
Stunning stuff there- Hard to chose a favorite
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Post by rockds on Sept 23, 2006 11:19:12 GMT -5
those are very nice, glad to see you back at it again, always like your work and the finished product gives me lots ao ideas.
robert
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Zoran
freely admits to licking rocks
Member since September 2005
Posts: 880
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Post by Zoran on Oct 15, 2006 4:09:52 GMT -5
Sorry, it took me so long. It was really busy period. Lots of work, my wife on trip to Croatia, I was alone with kids. Preparing my next trip to south Serbia. My comp at work crashed down... and so on. Thank you all for cool comments. I appreciate it. Sands, I am glad that I was able to help you. So, you joined hand drilling rock club  . To Mel, concerning formation of orbicular jaspers: "In general, if the melt is quickly chilled, it will solidify to quenched volcanic glass, whereas an equigranular to micropoikilitic microcrystalline groundmass is generated if solidification proceeds slowly enough to allow complete, homogeneous crystallization. However, depending on a variety of factors, including cooling rate, viscosity, chemical composition, and volatile content, undercooled felsic melts may experience a phase of high-temperature devitrification leading to the formation of spherulites instead of equigranular microcrysts (Lofgren, 1971). Individual spherulites commonly form spheres of radiating, fibrous quartz and feldspar crystals...: I tried to explain it in my words but than I found this on www-odp.tamu.edu/publications/193_IR/chap_03/c3_2.htm, explained in much better English then mine ;D. Basically this is one way of forming spherulites/orbicules but it is not always so simple. In nature it is very often that processes combine. You have to go from one concrete situation to another. For instance orbicular jaspers that I find in Serbia are situated in serpentinites, along fault zone. There is no direct evidence of volcanic activity. So, you have to undertake some laboratory investigation to have some facts to make conclusions on. Concerning petrified algae it could be one way of forming that spheroidal forms. I am not paleontologist so I am not too familiar with that processes, but it is possible. Orbicular jaspers from Serbia are not of that organic origin. I hope this was of some help. I am going to post some pics, today, but from Tuesday I am going to South Serbia - field explorations. So, I am going to be absent again, but by the end of the month, I will be back and then more present at RTH forum. |
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Post by rockyraccoon on Oct 15, 2006 4:13:12 GMT -5
zotika i don't know how i missed this but i'm glad you brought it back to the top. i love the under the sea one. beautiful work as always!
kim
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Sabre52
Cave Dweller
Me and my gal, Rosie
Member since August 2005
Posts: 20,494
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Post by Sabre52 on Oct 16, 2006 16:12:34 GMT -5
Wow Zotica! Thanks for the poppy jasper info. Very interesting that our poppy jasper we have here in Calif. often shows those radiating crystals, especially the Morgan Hill material and most all of ours is in metamorphic deposits associated with serpintine belts too. I'd think the first explanation more valid with regard to our orbicular rhyolites which seem magmatic in origin and commonly show the radiating crystals in spherules of various sizes The Sierra material I collect seems to fall into place under both explanations as there are examples which have very visable crystal structure and appear to be high temperature deposits but others that definately look like intrusions of low temperature silica into previously formed metamorphic rocks. I recently sent off some samples to another geologist to see what he thinks too. Certainly an interesting topic and I sure appreciate all your input.....mel
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