rockhoundoz
starting to spend too much on rocks
Member since March 2017
Posts: 131
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Post by rockhoundoz on Jan 16, 2019 19:16:47 GMT -5
Thank you for the photo & lighting advice, rocks2dust & gemfeller! Unfortunately, I didn't get a chance to attempt new pics today until after sunset, but gave it a shot anyways with the low light, using brushed steel. The colors are expectedly muted, looking much less colorful than full lighting, but I hope to try tomorrow midday. Those pictures above were all taken with the camera pointing away from the (setting) sun. The following picture was taken facing the sun, aka transmitted light. You can also see in all the pictures, how orienting the stones differently creates a certain amount of the yellow/pinkish color. Next, a couple other specimens from the same gravels. Until finding this next piece, never would've expected to find agate here. It's possible that this little guy travelled some 20/30 miles across drainages, from known ultramafic agate occurrences. & then some really nice clear gemmy smoky quartz (with poor lighting), & also noticed in this pic, that chunk of the material under duscussion, the orange light reflected/refracted(?) onto the white paper could indicate Rayleigh scattering: & one final pic, some nice serpentinite from those ultramafic deposits 20 miles away : )
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rockhoundoz
starting to spend too much on rocks
Member since March 2017
Posts: 131
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Post by rockhoundoz on Jan 16, 2019 18:54:21 GMT -5
Here's a stone I've been collecting in gravel from a location in east coast piedmont country. My immediate thought was quartz, either 'blue quartz', 'blue chalcedony' or even faded amethyst. Then I noticed that the color of the stone changes under different lighting &considered zoisite or iolite. Out of all the stones I mentioned, zoisite is the only one known to occur in this region via mindat. Here are two pictures. I suppose that having the white paper towel under the stones creates 'transmitted light'. Since blue chalcedony is known to be yellow/tan/colorless while having 'transmitted light', but appears blue when lighted from above, I suppose that's evidence for blue chalc. Hardness is around 7 & streak is white to colorless. Any opinions? Again, the lighting in the 2 pics are identical (indirect sunlight), the only difference is white background vs bamboo background. Thanks! That's some juicy looking stuff. I check for morganite and aqua using white paper when the stone is very pale. The white paper is a easy test with no gem tools. Next thing I notice is a definite color change but with a twist the bamboo there are at least 3 stones looking botroidal the others a agate look. Pinkish purple showing if you look close at the white paper plus the stones are turned upside down from bamboo picture Personaly instead of guessing what it is contact John Betts fine minerals or GIA and see what it's gonna take to have them ID it. If a color change stone due to lighting just couple bucks more with there ID if rare who knows. Just saying that's what I would do a trade the smallest stone for ID in writing! That's an interesting observation about the botyroidal shapes, dreamrocks, I didn't notice until you pointed that out! After closer observation, there are no botyroidal shapes on the surface, but there do seem to be internal features which repeatedly cause a reflection of sorts that appear globular. On that subject, I found several chunks of this stuff which have ribbon-like inclusions of an translucent whitish/grayish mineral, which isn't 'regular' enough in appearance that I'd call it agate, however, I assumed that those inclusions at least were chalcedony. Also, absolutely, I plan to take these in to a gemologist in person to have a better answer. May also attempt some microscopy in the meantime : ).
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rockhoundoz
starting to spend too much on rocks
Member since March 2017
Posts: 131
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Post by rockhoundoz on Jan 16, 2019 18:45:53 GMT -5
Also, what's the best/easy best 😅 neutral background for pictures of this kind ? Google "Rayleigh effect in quartz" and then try a few tests with different light. Thanks, good to know! So 'blue quartz' looks blue due to the rayleigh scattering effect, which is a result of light being 'scattered' by tiny ilmenite inclusions in the quartz. Coincidentally, ilmenite is listed to occur where these pieces were found. Blue chalcedony, looks blue due to the tyndall effect, which occurs based on the physical shape of chalcedony fibers in the stone.
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rockhoundoz
starting to spend too much on rocks
Member since March 2017
Posts: 131
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Post by rockhoundoz on Jan 16, 2019 0:57:34 GMT -5
Looks like chalcedony to me. Mineralogists tell us the difference between chalcedony and agate is that agate is banded and chal. is not. As for color, the only real test is in natural light with a neutral background. It's hard to judge from your images. Also, what's the best/easy best 😅 neutral background for pictures of this kind ?
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rockhoundoz
starting to spend too much on rocks
Member since March 2017
Posts: 131
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Post by rockhoundoz on Jan 15, 2019 23:39:13 GMT -5
Thanks to yall for the thoughts!
I know my cell phone pics aren't the best, but those colors from the two pictures I posted are actually pretty true to the colors my eyes see on the actual specimens in that lighting.
Definitely the background changes the color. The natural bamboo sets a nice contrast to highlight the blue color. The white background creates the same color/lack of color for the stones as when I shine an led through them, if that makes sense, which explains my conclusion about 'transmitted light'.
I'm close enough to chalcedony deposits that it seems like a very reasonable conclusion. I guess ultimately, viewing the crystalline structure under magnification would be conclusive for chalcedony vs 'rock quartz'?
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rockhoundoz
starting to spend too much on rocks
Member since March 2017
Posts: 131
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Post by rockhoundoz on Jan 14, 2019 21:39:27 GMT -5
Here's a stone I've been collecting in gravel from a location in east coast piedmont country. My immediate thought was quartz, either 'blue quartz', 'blue chalcedony' or even faded amethyst. Then I noticed that the color of the stone changes under different lighting &considered zoisite or iolite. Out of all the stones I mentioned, zoisite is the only one known to occur in this region via mindat. Here are two pictures. I suppose that having the white paper towel under the stones creates 'transmitted light'. Since blue chalcedony is known to be yellow/tan/colorless while having 'transmitted light', but appears blue when lighted from above, I suppose that's evidence for blue chalc. Hardness is around 7 & streak is white to colorless. Any opinions? Again, the lighting in the 2 pics are identical (indirect sunlight), the only difference is white background vs bamboo background. Thanks!
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rockhoundoz
starting to spend too much on rocks
Member since March 2017
Posts: 131
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Post by rockhoundoz on Nov 5, 2018 13:59:47 GMT -5
Fluorite is soft and scratches with a pocket knife blade. Does this stone scratch with a pocket knife blade? (Kentucky has fluorite deposits) ETA and I see a cube in one of the original pictures. ETA x2 Bottom right side looks like a cube to me. That would be amazing to find a big chunk of purple fluorite out here! adam, rare but possible because there was a nearby mine that produced fluorite some time ago, in central KY. If I recall correctly, there was also even fluorite found near Georgetown KY. Apparently, fluorite is also possible inside geodes from many ky locales. Probably easy to overlook or mistake fluorite for the waaay more common calcite in geodes & agates. This piece though is certainly chalcedony, basically ancient inland sea fossilized chert, but with somewhat agatized areas in the 'rind' & perhaps oolites too. I will post the results of working this stuff : ), have a small carving in mind if I can get a nice piece fracture-free!
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rockhoundoz
starting to spend too much on rocks
Member since March 2017
Posts: 131
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Post by rockhoundoz on Nov 2, 2018 16:18:47 GMT -5
Thanks all! I put it in the saw, took off a small end cut & like yall said, became clear that it's purple chert. We have a ton of oolite out here, various sea creatures mixed into the chert, as you noted Peruano, & also a ton of coral 'head' fossils. These coral heads are what most ky agates are replacing, & this purple guy has that general shape & form. Also, lost the nice overcast daylight here & this round of photos suffered in terms of focus and color, heh.. Then, after taking 1 slab off the end, seemed like the fractures (going in many directions throughout the rock) were at least somewhat healed, so I decided to reposition it & cut along the bigger face. In particular, aiming to target the more colorful & 'patterned' skin/rind. It's in between the 6-7 hardness. Softer than ky agate but also it's not the softest chert around. It flakes away quite nicely too. Fracture is conchoidal, but preserves that cell pattern which is throughout the rock (can't remember ever seeing a similar cell pattern after cutting 100's or a thousand pieces of local chert, fossils, coral etc over the last 10 years back home in KY). The cell shape is hard to see in my poor pics, but if ya saw it in person it's all throughout the rock. Highly translucent. Regarding fossil bone, I once read from the University of KY geology dept. that the most common question they receive from the public is not just whether some given rock is a dinosaur bone, but what type of dinosaur 😅. Of course it's basically never dino bone. Fortunately a little wishful thinking never hurt! Also, this chert was found just a stones throw (relatively) from a location where many complete fossil dinosaur skeletons were once found, in the same geologic & physiological setting, so I'll keep hoping to find some one day!
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rockhoundoz
starting to spend too much on rocks
Member since March 2017
Posts: 131
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Post by rockhoundoz on Nov 2, 2018 12:44:53 GMT -5
I can't help with ID, but I have to say- You got a sweet looking rock there! Thanks! Not to sound too weird, but I was so excited about finding it that I stayed up until 3 am, haha..
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rockhoundoz
starting to spend too much on rocks
Member since March 2017
Posts: 131
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Post by rockhoundoz on Nov 2, 2018 12:42:14 GMT -5
Have a way to take a slab off it? Yes, it's just a bit intimidating to think about cutting it at the moment.. If someone assures me that it's not dinosaur bone, then I'll feel a lot more comfortable slicing it up ; ). It's also a tricky one to figure out for orienting the cuts because of the heavy fractures, which I'm leaning towards thinking are unhealed so far. Very open for any thoughts/advice on the lapidary side though!
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rockhoundoz
starting to spend too much on rocks
Member since March 2017
Posts: 131
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Post by rockhoundoz on Nov 2, 2018 11:34:46 GMT -5
Found this rock yesterday & my 1st thought was that I had finally found a piece of the infamous Kentucky purple chert. I've long heard about a purple chert material coming from Kentucky, said to knap very well, and have never even seen a piece in person let alone found one. Seen plenty of maroon, pink, red etc.. So I was very happy just to find this as chert, but then after I cleaned it up, noticed it has a clear 'cellular structure' pattern. I believe it to be fossilized something. Maybe 'oolite' as I've learned about from yall on this here website, or other bryozoan/simple marine creature, but one can always hope, heh. Anybody have a possible ID? Thanks! It's about 6 inches long, weighs about 3 pounds, & was found in quaternary alluvial gravel, sitting right on the surface, karst/cave geology all around. Few pics of the shape & surface texture: Some pictures to show the 'cellular structure' I mentioned: This next picture is much closer to the middle/core of the rock, shows a texture that looks pretty different than the parts closer to the surface (dry & wet): The purple is so much more beautiful & intense than I can capture in these low grade photos, 😅.
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rockhoundoz
starting to spend too much on rocks
Member since March 2017
Posts: 131
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Post by rockhoundoz on Sept 30, 2018 22:40:46 GMT -5
Cool stuff. Thanks for sharing. I like the ribbon agates. And I had forgotten that Poland has Thundereggs. Yep, the ribbon agates are very colorful little ones! I've only cut a few of the thundereggs, from nowy kosciol 'new church', looking forward to cutting more but my saw is temp. down 😅.
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rockhoundoz
starting to spend too much on rocks
Member since March 2017
Posts: 131
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Post by rockhoundoz on Sept 29, 2018 13:23:18 GMT -5
Over the past few months, I was lucky to collect some rocks in southern Poland & on a roadtrip out west to Oregon. The sites in Poland are heavily utilized, hard to locate & take a lot of work, fortune, or both to find anything of good quality. Especially the famous Płoczki area. Płoczki: 1st piece, my favorite find from this site, pictyre of rough surface, then middle cut. Pretty sure it was intentionally left behind as I found it on the surface. It was pretty 'rotten/decomposing' as a display piece overall, but plenty of lapidary potential. 2nd Płoczki rock: Then Polish ribbon agates: & other sites in Poland: 1st one looked like a good agate outside, but ended up being surprised by the nice green/brown chert. More: Next up is Eastern Oregon stuff: Final picture was a little surprise back home in Kentucky, from out in the western edge of KY geode zone. Far from the typical Kentucky agate area. Picked up a typical looking chunk of oolite/fossil conglomerate & was happy to find this little 1/2 inch agatized bit. It reminded me of the look of botswana agate & never seen anything similar in KY before.
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rockhoundoz
starting to spend too much on rocks
Member since March 2017
Posts: 131
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Post by rockhoundoz on May 21, 2018 1:08:14 GMT -5
Hi, I would like to buy box #3 please, AZ chrysocolla, thanks!
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rockhoundoz
starting to spend too much on rocks
Member since March 2017
Posts: 131
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Post by rockhoundoz on May 13, 2018 22:04:08 GMT -5
Rocks2dust, it does look very much like oak in the small patch of grain that's highly visible. Spruce would be about the only other wood looking similar at all. The poor lighting in my picture made the lighter colored zones seem more white or creamy. There are some fine white/opaque inclusions & also similar white 'crust' on the rock, which do feel slightly waxy, but it won't scratch a bit by my hard steel knife & looks chalcedony like. Here's a better picture showing that it looks more transparent & agatized overall: For the thundereggs, the top 3 and the bottom-left all look like Priday area eggs. The cut egg could be Mcdermitt, Priday or ?? I was thinking "Lucky Strike" egg on the cut... I see a Richardson Ranch egg in the bunch too (Second one from the left,on top..)...Probably Blue bed or Red bed.. Fossilman, does the red/blue bed refer to the color of the chalcedony? The 2nd from left top was the one with what I think of as classic star-shaped blueish, T. Egg from OR. The larger egg from picture 9, on the bottom, far right seemed particular interesting & beautiful to me-
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rockhoundoz
starting to spend too much on rocks
Member since March 2017
Posts: 131
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Post by rockhoundoz on May 12, 2018 20:11:54 GMT -5
Here's a picture of the piece of pet. wood that I thought was most interesting, & that was small enough to cut. Still in saw, cutting it into two .75" slabs after some deliberation. It was nicer than I anticipated. Rock was also in pictures 2, 4 & 5. It looks fairly similar to AZ wood that I'm seeing online, but very different from the AZ wood I've collected.
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rockhoundoz
starting to spend too much on rocks
Member since March 2017
Posts: 131
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Post by rockhoundoz on May 12, 2018 14:41:47 GMT -5
That purplish one looks more like Holley Blue than Blue Lace to me. That occurred to me, too. I even had a piece of Ellensburg that looked similar (depending on how closely the colors of agate and matrix on my monitor match the real thing). Hehe, now we're talking ! Thanks Amygdule & Rocks2dust! I spent many, many days searching around the Ellensburg area for the elusive blue agate while living in Washington state. Found tons of nice rocks, mostly gray/black/white agate, crystal geodes (love-stones as an old local rockhound called them) & also some really nice bluish-greenish seam agate, but never found any E. blue. Only dreamed of holley blue since the location had already been closed. When I saw this piece, these PNW agates did occur to me, but I wrote it off as a fantasy 😅. For one thing though, up until this point, I have only seen domestic material in the collection where these were found. Guess I'll bring that rock out to the PNW on my next trip to have it ID'd. It does look more purple than blue in person. & thanks for the thunderegg id rocks2dust! After cutting a couple more eggs, & finding (what my limited experience considers) the classic Oregon blue-grey waterline agate centers, that seems likely. Started cutting unknown agate from pic #11, here's a couple slabs.. Any ideas?
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rockhoundoz
starting to spend too much on rocks
Member since March 2017
Posts: 131
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Post by rockhoundoz on May 11, 2018 20:22:15 GMT -5
Thanks Toiv0, I do hope it's WI moonstone! Much cooler to me than some random labradorite. Gemfeller, 'preciate it! I guess African material was the only thing that came to my mind, but it seemed less blue, less banding & no druzy, which differed from the African blue lace I've had. Reckon this piece could just be low quality blue lace from the (really) old continent . & <'))))>< Fish, Paul Bunyan plume sounds good! While looking at google 'red plume agate' images, paul Bunyan & Carey plume were the 2 that seemed most similar. Thanks for the thought!
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rockhoundoz
starting to spend too much on rocks
Member since March 2017
Posts: 131
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Post by rockhoundoz on May 11, 2018 18:23:04 GMT -5
Thanks fernwood, that would be great! I was bummed when I missed the WI moonstone up for sale/auction some time back.
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rockhoundoz
starting to spend too much on rocks
Member since March 2017
Posts: 131
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Post by rockhoundoz on May 11, 2018 17:21:56 GMT -5
Howdy ya'll! Purchased a bunch of rocks, & I'm terrible at ID, since I usually collect my own & therefore know exactly where they're from.. First up is this plume agate, was basically a freebie add-on, much nicer than I expected! California maybe? Got 6 good slabs, all virtually perfect/fracture free except for one small fracture on the edge of one slab. 1. Then 55 lbs of petrified wood. Mostly black, but some has browns & some has nice wood patterns. Maybe not all from same location. 2. 3. 4. 5. Then, mystery agate. This one is mildly blueish/purplish. Doesn't look like African material to me. Banding is white & rather faint. Another freebie. 6. 7. Then, mystery labradorite. Any ideas? Looks to me like it has schorl included. 8. Then, thundereggs. I have very little thunderegg experience. All from same location or maybe not? 9. 10. Only cut the one so far, greener plumes than it looks: & finally, another mystery agate. Texas? Mexico? I'll post more pics soon after cutting it. Not sure of best cutting approach either? Maybe just do the easy thing and clamp it along the flat bottom and cut along the broken face? Or is it worth it to try to cut it at an angle to maximize the height of the seeming sagenite spray at the bottom? 11. Thanks!
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