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Post by gmitch067 on Apr 23, 2018 1:44:13 GMT -5
I am considering purchase of Turritella shells from The Rock Shed and need advice on how to polish them without destroying their shape. I was considering using either my Mini-Sonic-4 or Lot-O because the slower action would minimize breakage (with the right cushioning media... whatever that will be).
Question-1: Should I consider using 220 SiC... or will that be too aggressive a grit to subject them to? ... Maybe bypass the 220 and just go with AO-500, AO-1000, and AO-14000???
Question-2: Large/Small ceramic media ...or... already polished pea-sized quartz gravel as filler/cushioning???
I have not purchased the shells yet.... Just doing research first before I jump in. The little suckers are rather expensive and I don't want to destroy them. They look kind of cool and I am thinking of sending a bunch to my Grand-Kids to share with their school buddies and buddettes.
Thanks. Glenn
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,154
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Post by jamesp on Apr 23, 2018 3:48:15 GMT -5
I never have tumbled them Glenn.
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Post by Drummond Island Rocks on Apr 23, 2018 7:25:39 GMT -5
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Post by fantastic5 on Apr 23, 2018 7:29:57 GMT -5
I looked on the website to get an idea of the item your referring to. Are you thinking about buying the crushed Turritella tumbling rough? I didn't see just loose shells, but maybe I didn't look in the right spot.
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Post by fernwood on Apr 23, 2018 7:42:38 GMT -5
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Post by gmitch067 on Apr 23, 2018 8:12:54 GMT -5
Thank you fernwood for posting the link. Sooo... Shells (agatized???)... Not crushed tumbling rocks. Glenn
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Wooferhound
Cave Dweller
Lortone QT66 and 3A
Member since December 2016
Posts: 1,423
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Post by Wooferhound on Apr 23, 2018 8:13:35 GMT -5
I have tumbled shells on 2 occasions, including some self collected Turritella shells from the Tennessee here in North Alabama. Both times I did shells they were done the same way. Placed the shells into a Lortone 3A 3 pound tumbler with #80 Grit. Only shells and grit less than half full in the barrel with water filled even with the top layer. Tumble for a week or two in Stage 1, they smooth out quick. No need to add or change grit cause it dosen't breakdown. Then normal 220, 600 and polish stages. Only Shells with the grit, less than half full with water filled to the top layer. The Turritella shells I collected had a paper-like coating on them, as soon as that coating is removed they will be smooth and ready to push past the Course Stage. Due to the spiral nature of the shell. they will need to be washed a coupla times between each stage. I tried to use plastic beads in the fine polish stages. but would never do that again because they get lodged in the opening on the shell and can't be removed without damaging the shell. The shells will polish themselfs fine shell-on-shell without the need for any media in polish. I looked for my polished Turritella shells but they weren't findable so I included a picture of some ocean found shells as an example...
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Post by Drummond Island Rocks on Apr 23, 2018 8:20:36 GMT -5
The ones I have seen are agate. They are goniobasis shells which is what is in the Turitella. Chuck
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Post by gmitch067 on Apr 23, 2018 8:20:57 GMT -5
I have tumbled shells on 2 occasions, including some self collected Turritella shells from the Tennessee here in North Alabama. Both times I did shells they were done the same way. Placed the shells into a Lortone 3A 3 pound tumbler with #80 Grit. Only shells and grit less than half full in the barrel with water filled even with the top layer. Tumble for a week or two in Stage 1, they smooth out quick. No need to add or change grit cause it dosen't breakdown. Then normal 220, 600 and polish stages. Only Shells with the grit, less than half full with water filled to the top layer. The Turritella shells I collected had a paper-like coating on them, as soon as that coating is removed they will be smooth and ready to push past the Course Stage. Due to the spiral nature of the shell. they will need to be washed a coupla times between each stage. I tried to use plastic beads in the fine polish stages. but would never do that again because they get lodged in the opening on the shell and can't be removed without damaging the shell. The shells will polish themselfs fine shell-on-shell without the need for any media in polish. I looked for my polished Turritella shells but they weren't findable so I included a picture of some ocean found shells as an example... Thank you Wooferhound . I really don't want to smooth them out... The sharp edged spirals are what attracted me in the first place. The Rock Shed write-up says they come from Morocco.
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Post by gmitch067 on Apr 23, 2018 8:23:43 GMT -5
The ones I have seen are agate. They are goniobasis shells which is what is in the Turitella. Chuck Thank you Chuck.... the shell on the right is what I hope to get out of this... but with sharper corners (?).
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Post by Drummond Island Rocks on Apr 23, 2018 8:24:23 GMT -5
Turitella is a seam type of material and the top layer always has semi-loose shells on it. I would imagine the soil around the seam would have lots of them in it. This picture shows how they look on the top of the seam. Chuck
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Post by gmitch067 on Apr 23, 2018 8:28:30 GMT -5
Turitella is a seam type of material and the top layer always has semi-loose shells on it. I would imagine the soil around the seam would have lots of them in it. This picture shows how they look on the top of the seam. Chuck Now!... THAT is down right NEAT looking... Very instructional specimen. That should be used at the school's show-n-tell. I like+++
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Post by rockpickerforever on Apr 23, 2018 8:31:51 GMT -5
I like the agatized individual shells tumbled better than the chunks of rough. John herchenx did a trip report where he collected some of them - Trip report: Turitella agate and Stromatolite
Doesn't have a photo of them after polishing, but at least a before pic I know I've seen pics of them tumbled, they are very cool looking.
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Post by Drummond Island Rocks on Apr 23, 2018 8:48:28 GMT -5
I like the agatized individual shells tumbled better than the chunks of rough. John herchenx did a trip report where he collected some of them - Trip report: Turitella agate and Stromatolite
Doesn't have a photo of them after polishing, but at least a before pic I know I've seen pics of them tumbled, they are very cool looking. Yep, I miss seeing all of Johns trip reports and awesome photos. I was lucky enough to get some really nice Turitella from him after one of his trips. Chuck
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Post by rockpickerforever on Apr 23, 2018 9:03:35 GMT -5
I, too, loved his trip reports. Great pics and reports, always felt like you were tagging along! I did vfind his thread where he had posted pics of the completed tumbles from that trip, including the goniobasis. Unfortunately, all the links were broken. Not pbucket, but google. Instead of a ransom notice, all his pics in that thread have been replaced with an exclamation point in a white triangle. Dang, but I wish I could see those pics!
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Fossilman
Cave Dweller
Member since January 2009
Posts: 20,680
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Post by Fossilman on Apr 23, 2018 9:08:03 GMT -5
In my opinion, I never tumble fossil species....Tried tumbling Baculite once, it was a disaster..It took the characteristics away from the prehistorically creature.. When I have plates of the Turitella, I just give them away or barter them.. I do have singles that did fall of the death plates, I did keep them, as they were found.. Good luck...
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Post by fernwood on Apr 23, 2018 9:17:56 GMT -5
Please keep us posted. Maybe post a photo of what you receive for grit advice. Keeping the sharp edges could be tough. The Rock Shed appears to be full of helpful advice. Try contacting them for recommendations. There is another recent thread here somewhere by someone who already purchased these and is working on them. Will see if I can find it.
On photos in past threads. I am overloading my computer with thousands of rock photos. Burning CD's for backups and storing them in my safe. One can never count on any web photo hosting place staying around or not holding photos ransom/deleting them. I never know when I will need easy access to photos of rocks.
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Post by Peruano on Apr 23, 2018 11:56:28 GMT -5
I tumble polish turitella slabs and while I preshape them, they have a way of changing my plan in the vibe. Basically some parts of the matrix are solider than others and some of the shells will erode out in the process. However, the slabs can be recovered with a bit more judicious grinding after the vibe process. I have not checked the rock shed site, but I'd be surprised if they are selling loose shells of Turitella. Howver even if they are, they will be fossilized and quite different in hardness from nonfossilized shells. The minisoic should be fine, and the 220 grit should be ok but potentially not necessary. When I polish slabs its the black matrix that polishes and to my eye the shells are less so. Anyone polishing nonfossilized shells probably should be careful to dispose of the chalky slurry that they generate. There's some controversy as to whether its good to breath or ingest. I doubt the shells in the Turitella fossils pose the same risks, but the matrix does stink when you grind on it (like many organic origin materials). You can cab the Turitella slabs too, but they are easier to polish in the vibe. They probably would not stand up to a rotary.
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Post by gmitch067 on Apr 23, 2018 13:00:33 GMT -5
I tumble polish turitella slabs and while I preshape them, they have a way of changing my plan in the vibe. Basically some parts of the matrix are solider than others and some of the shells will erode out in the process. However, the slabs can be recovered with a bit more judicious grinding after the vibe process. I have not checked the rock shed site, but I'd be surprised if they are selling loose shells of Turitella. Howver even if they are, they will be fossilized and quite different in hardness from nonfossilized shells. The minisoic should be fine, and the 220 grit should be ok but potentially not necessary. When I polish slabs its the black matrix that polishes and to my eye the shells are less so. Anyone polishing nonfossilized shells probably should be careful to dispose of the chalky slurry that they generate. There's some controversy as to whether its good to breath or ingest. I doubt the shells in the Turitella fossils pose the same risks, but the matrix does stink when you grind on it (like many organic origin materials). You can cab the Turitella slabs too, but they are easier to polish in the vibe. They probably would not stand up to a rotary. If the 220 grit SiC is "potentially not necessary" then I think I will try going straight to AO-500 in the vibe. I have not made any determination which vibe to use... certainly NOT the UV18... too aggressive. If the AO-500 looks inadequate as a start point, I will drop back to a short 220 grit SiC run. The write-up says they are "Chalcedony replaced Turritella shells" with a 7-Mohs hardness. The dangers are probably minimal... but I will dispose of the slurry in my "No Grow" zone... Thanks for the warning! The Lot-O is certainly impressive... however the Mini-Sonic-4's with it's speed adjustment is also impressive... still undecided. Maybe I will split a 5 lb order between them and let the results do the talking. I just ordered 5 lbs of the shells (not the sedimentary clusters). therockshed.com/crushedrock2.htmlNext thing to look at is whether to use polished pea gravel or ceramic media. Question: Is there a size of gravel or ceramic media that does NOT work well with the Lot-O or Mini-Sonic??? (I seem to remember a comment somebody made about this - jamesp maybe??) Thanks for the inputs All! Glenn
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Post by Peruano on Apr 23, 2018 13:05:00 GMT -5
Your shells are going to be small so you should be able to get by with really small filler. The only time I have trouble with small filler is when its in with very large slabs and hangs in the bottom of the bowl.
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