tag:blogger.com,1999:blog-1580629844893014592.post8865167991137887888..comments2024-03-15T17:32:22.672-06:00Comments on CSMS GEOLOGY POST: CHASING ARIZONA ONYXMikehttp://www.blogger.com/profile/06840636909756120255noreply@blogger.comBlogger5125tag:blogger.com,1999:blog-1580629844893014592.post-41257902731950639752023-11-13T14:24:43.474-07:002023-11-13T14:24:43.474-07:00from "simon and schusters guide to rocks and ...from "simon and schusters guide to rocks and minerals"<br /><br />travertine components: <br />calcite or aragonite, with limonite impurities; frequent fossils and imprints, especially of plants.<br /><br />type: chemical sedimentary rock<br />class: carbonatic rock<br /><br /><br />CALCITE:<br /><br />group: carbonates<br />composition: CaCO3<br /><br />Appearance: Rhombohedral, scalenohedral or prismatic crystals, often intergrown or twinned. Variable color (colorless, white, pink, green, yellow, etc.). Occurs in masses: compact, microcrystalline (limestones), saccharoidal (marbles), fibrous (alabasters), concretionary (stalactites and stalagmites), pulverulent, oolitic, etc.<br /><br /><br />-technically, calling banded travertine, banded calcite, would be correct, if the travertine is made up of calcite. <br />-technically calling banded marble, banded calcite, would be correct, as marble is a coarse grain variety of calcite<br />-technically calling banded alabaster, banded calcite, would be correct, as it is the fibrous variety of calcite<br /><br />basically, they are all calcite...and if they are banded, they can be considered banded calcite.<br /><br /><br />Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-1580629844893014592.post-68887960038699721122023-11-13T12:44:12.708-07:002023-11-13T12:44:12.708-07:00the black canyon onyx and grand canyon onyx, are m...the black canyon onyx and grand canyon onyx, are mostly banded calcite. tests with acid will easily confirm if an "onyx" is chalcedony or carbonates like calcite. travertine is a sedimentary rock, almost pure calcium carbonate, but a different structure than calcite. i have put many pieces of arizona "onyx" into a light acid bath, called "acid washing" and they were polished by the acid. i do not believe you can polish travertine with acid, as it is said to destroy the finish even in weak amounts. but acid will destroy calcite as well, if not done properly. my personal opinion is that arizona "onyx" and mexican cave onyx etc are mostly types of banded calcite. i even have a piece of "onyx" from pakistan, and i was able to polish it with the same methods i use for calcite. which to me, says that it is mislabeled calcite. many items being sold as banded travertine, look like banded calcite as well. as calcite is the "commonest carbonate" according to a book i am referencing, it would make the most sense for these items to be calcite, not travertine. <br /><br /><br />whoever started calling a carbonate, onyx...really, truly messed things up. we need a new definition/clarification for "onyx." Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-1580629844893014592.post-36380438221845668532017-03-12T11:49:02.537-06:002017-03-12T11:49:02.537-06:00I am currently creating hand carved art pieces out...I am currently creating hand carved art pieces out of the "onyx" from the Mayer mine in Arizona my customers want to know the metaphysical properties of the stone but I can't be sure what it actually is it dose not look like any travertine I have ever seen it's labeled as Black and Grand Canyon Onyx it looks like a Banded Calcite but is to hard to be calcite<br />The black canyon is brown red black and white<br />The grand Canyon is white black yellow green and brown<br />I was hoping you would share your thoughts on what it is Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-1580629844893014592.post-68999518886391932502016-06-17T21:40:54.520-06:002016-06-17T21:40:54.520-06:00I have the same question. I'm a Midwesterner ...I have the same question. I'm a Midwesterner but have picked up some nice specimens off of Spur Cross Rd. and far East off of Cave Creek Rd. We were there last week and I picked up a beautiful yellow-green stone about six inches long and very smooth. Any ideas on what it is? Thanks so much.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-1580629844893014592.post-80157437191451700522016-02-22T18:29:07.632-07:002016-02-22T18:29:07.632-07:00Hello, thanks for this great article. I'm a r...Hello, thanks for this great article. I'm a rockhound and recently visited the Seven Springs area for jasper, which is pretty nice quality. Just by chance, I was driving on some of the residential roads above Carefree and spotted the tip of a jasper-looking rock at the side of the road, in a gully. I was able to dig it up (~80lbs) and after cleaning it off I'm wondering what I've got. It looks like it has bands of red jasper, maybe some cream-colored onyx, and a couple knobs of more clear agate (or quartz-looking) material included for good measure. I don't want to cut or break it up - rather, I'd like to clean it up and see if I can make it an attractive piece for display. When the stone is wet and in the sun, it shows off a lot of color - reds, orange, yellow, cream. But when it's dry and inside, it's a rather ordinary tan rock. ;-) You may not know the answer to this question but I'm curious if it's advisable to treat the rock with some kind of sealant which will bring out the color, and give it a little shine. I was thinking about getting some stone floor sealant from the home improvement store and trying that. The rock has so many indentations and rough areas that I don't think it will be feasible to try and grind/sand it down to achieve a smooth surface, but i do have the tools for that. Any advice you could provide would be much appreciated. I'd like to bring out the best colors in indoor lighting conditions, but I've never tried sealants before. Anonymousnoreply@blogger.com