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Post by rmf on Dec 10, 2020 11:54:11 GMT -5
rockhoundmn Yes a scratch test is done dry as you have stated. It is a relative test. Take a glass jar and try to scratch with a pocket knife. It slides over the surface no scratch. they are about the same hardness. If the rock is harder than the agate, the agate will not scratch it and should glide over the surface about like the pocket knife and the glass jar. For softer rocks like feldspars the agate will leave a visible scratch possibly with some white powder which is the pulverized rock scratched out of the softer rock. for equal hardness you still may see white powder where they two rocks grind each other but you should not be pushing so hard you pulverize the rocks. Your observations are right on the $$. once you get a feel for what you are looking at you will not do hardness testing, your eye will take over and only when it gets stumped will you test. You will also learn that quartz and agate are the same hardness but not the same toughness. Agates like the lake superiors you have are tougher than quartz and it is good to separate the quartz and quartzites out from the agates if you have larger diameter tumbler drum like a 6lb or 12lb drum. The toughness does not matter as much in the 2-3lb tumbler drums. Agate is composed of layers of quartz and moganite. this layering makes agates tough. agates will take more impact force than quartz. Also for rocks that you think are harder not just equal hardness. try to scratch your agate with the "harder" stone. sharper edges scratch easier but are not always convenient.
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Post by rmf on Dec 9, 2020 23:16:11 GMT -5
Here's what happens to a thumb when a person decides to make a ring-sized cab with a dremel. Not advisable.
When I was in high school I went to a guys house to learn how to make spheres. He did everything by hand, only home made equipment. I ground the sphere by hand in a steel pipe. After two days of grinding all the skin on my palms was so thin even warm water felt hot.
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Post by rmf on Dec 9, 2020 23:11:46 GMT -5
rmf - very true, 25-40 extra pounds depending on if its the 3 or 1 year old! It's good though, forces me to be a little more selective (a LITTLE). I guess that will encourage you to get them walking faster. I my case my son wants nothing to do with rocks. We took him to too many hunts/shows.
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Post by rmf on Dec 9, 2020 5:14:40 GMT -5
chandler search on your favorite web engine for radiolaria and you will find similar images.
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Post by rmf on Dec 9, 2020 5:10:13 GMT -5
You said, "I'm fairly new to rockhounding, but I'm already obsessed and my favorite thing to do is surface hunting Graveyard Point OR with one of my two daughters in the backpack." I don't know how big your daughter in the back pack is but if you kick her out you can probably carry at least 20 more pounds of rock back:)
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Post by rmf on Dec 9, 2020 4:44:00 GMT -5
What rock formation is this from? I have seen skin images that look similar but most do not. the strata might tell us if the rock is from the correct time period. See if the state has a geological quadrangle of the area. locate where you found the rock and the map will tell you what formation(s) you were in. If you were not well into the Cretaceous-Jurrasic it is not dino skin.
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Post by rmf on Dec 5, 2020 15:06:37 GMT -5
The problem is I want to know what the name of 8 and 14 are. Does someone out there have any guesses?
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Post by rmf on Dec 5, 2020 14:36:16 GMT -5
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Post by rmf on Dec 3, 2020 12:05:12 GMT -5
jasoninsd said Birdseye rhyolite and I agree. Definitely looks like a rhyolite I don't know. Can't recall ever seeing rhyolite with drusy on it. Agreed, I also missed the agate around the orbs at the top. How hard is the white material in the center? How hard is the red material in the center (not the pheoncrysts)?
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Jasper?
Dec 3, 2020 12:02:36 GMT -5
Post by rmf on Dec 3, 2020 12:02:36 GMT -5
How hard is it? H=7 chert or maybe a jasper
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Post by rmf on Dec 2, 2020 18:53:03 GMT -5
chandler can't tell due to erosion on the exterior. Need a fresh break to tell.
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Post by rmf on Dec 2, 2020 18:50:43 GMT -5
jasoninsd said Birdseye rhyolite and I agree. Definitely looks like a rhyolite
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Post by rmf on Dec 2, 2020 18:46:42 GMT -5
rockhoundmn In my opinion start with the best, most consistent rough to get a good result right out of the gate. Follow the store bought recipe that comes with the tumbler to get a feel for what you are doing. So what is your best stuff. Image 6 is mostly Lake Superior agates. they will allow you to see your results with a uniform product of hardness 7. Use one of those agates as your scratch test master until you can visually tell agates and jaspers. Fill the rest of the drum with the stuff that won't scratch from image 5. This is your first batch. Fill the drum about 75% full and do not be afraid to add some pea size pieces to fill up the gaps. Do not use the dremel on this first batch. Learn tumbling first then try the dremel. You can always retumble a stone. Using a dremel is an expensive way to shape rocks due to the burs and time. Be careful not to get the rocks too hot when you use the dremel and wear a dust mask you don't want silicosis. For really dirty rocks you can tumble for a day or 2 in coarse and then wash and sort. You have a great start and some really nice lakers. Have fun!
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Post by rmf on Dec 2, 2020 18:13:55 GMT -5
What @hankrocks said about pea gravel. I also use previous fines. I had a customer that wanted me to cut some cabs from broken china plates. I got the ugly scraps which I broke up and used as ceramic pieces. they worked fine but yes the grind up. That is why for normal agate and jasper I fill with pea gravel. I have also tumbled a material that to get a good polish I had to mix 50% plastic pellets and 50% indoor - outdoor carpet pieces to get a good polish on varing hardness. I think jamesp does a lot of glass and uses ceramics for that so you just have to figure out what your batch needs. I have also tumbled with wooden pegs in polish.
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Post by rmf on Nov 29, 2020 16:06:14 GMT -5
I have an older (30yrs) www.gesswein.com/c-44-ultrasonic-jewelry-cleaners.aspx. It has the option of 0-60 min or on continuously. I use it to clean vugs out of cabs when they are full of polish. I steal laundry detergent from my wife when she is not looking. an ultrasonic will heat the water due to friction but starting with host is good and the detergent helps lower surface tension... Soft things like the plastic lenses in glasses can be damaged if left in too long. Soft rocks can be damaged if left in too long. the finish on jewelry can be damaged if left in too long but with care I would try any of those things except the plastic lenses since most lens material has additional coatings that can be damaged. I have cleaned brass with the same water and detergent. use low foaming detergent. It is a great cleaning tool.
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Post by rmf on Nov 27, 2020 20:43:40 GMT -5
I have seen it used on turquoise and silver
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Post by rmf on Nov 27, 2020 20:35:33 GMT -5
kyoti said, "Could you all tell me what is safe to tumble? Will a larger rock pulverize the smaller agates or if I fill the barrell to 80% will they survive? I don' t want to ruin good rocks. Should I just do a few big rocks and fill the rest with gravel? " Q1 If you are just starting out use the pinkish rock second from the left to test your other rocks. It looks like quartzite. It is hardness of 7. If it scratches rocks they are too soft. Start with a batch of agate or jaspers since they are easier to get a good polish on just starting out. Yes fill your barrel about 80% full including sizes down to 1/4". Small stuff acts as cushioning. Not in a 6# drum you need more cushioning for things like quartz and quartzite to get a good polish. the good news is that if you out grow the 6# drums the Qt66 will also use the 12# drum. The Qt66 and the QT12 are the same base with different drums.
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Post by rmf on Nov 26, 2020 4:39:08 GMT -5
you guys have it all wrong 12 then 8
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Post by rmf on Nov 25, 2020 15:27:52 GMT -5
The labradorite will grind away noticeably faster than the amethyst. This means the softer will be ready way to move on to the next grit way sooner than the harder. If it were me I would wait until I had enough of either to do a batch. Just as an FYI I have found a Lortone 3A tumbler barrel lets you tumble anethyst and agate together start to polish with no problems. But when you go to a 6# or 12# drum polishing them together results in the amethyst being chipped and frosted around the edges. This is due to the rock falling farther in the tumbler due to increased diameter as well as amethyst being not as tough as agate even though they are the same hardness. So toughness does not equal hardness.
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Post by rmf on Nov 24, 2020 3:08:27 GMT -5
so the question is what equipment do you have? That would determine what you do. If I had a grinder with a variety of wheels I would do just exactly what pauls said polish the face of the first image leaving the rest rough. If you have a rock tumbler then I would pour the cavity full of epoxy and tumble the rock. Once polished all around I would dissolve the epoxy out with acetone.
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