Carnelian - African

Wow, you abolutely nailed those!!! Outstanding job!
-Don

Gorgeous tumbles, Sparkles. Carnelian is always a favorite, and yours has great color.

Wow, where did you come from?? lol... Those are awesome!! I'm looking forward to seeing more of your stuff.

Beautiful batch, Spark!!

You're obviously an old pro at this. I'd think the 1 1/2 pound barrels would test our patience even more.

Rich

Sign of a man with great patience: stating that this tumble took "only" 10 weekly recharges! Great stuff, fantastic shine, an inspiration!

WOW!!!!! those are great!!!!!!!


Roger

Excellent batch!

I've tumbled a few carnelians in mixed batches before but never had enough on hand at one time to do an exclusive batch of them. It's one of my favorite tumbling stones but the two local rock shops here just charge too much for the rough.

Oh Oh! We have another winner with the shine! I'm putting this tumble into the same class as rollingstones (Don) who we all hold in very high esteem for his superior finished tumbles!

I can see the whole batch drilled...strung & hanging around my neck as I type!

Well done!

Hi

I shall endevour to explain my process a little more clearly. I run 4 rotary tumblers carrying a total of 10 identical 1.5lb barrels, and I use standard Silicon Carbide tumble grit for all my processing. Barrels are loaded in the conventional fashion, with approximately 2/3rds stone, a measure of grit and then topped up with water to just below the level of the top stones in the barrel. I use approximately 10% of the total barrel load of stone by weight in Silicon Carbide - i.e with my small barrels running about 500g of rock, I use 50g of grit per load. The barrel runs for 6.5 days before I rinse off everything, sort the stones (removing any that are ready for the next stage) and reload the barrel. Reloading the barrel with fresh grit and water and continuing the process. I have reused slurry in the past - however this gave me no increase in the measured effectivness of the process.

I have studied the action generated by my tumbling in several ways, including weighing the batch before and after processing to measure the actual reduction of material from the process. This varies considerably between rock varieties, but for the Carnelian batch an average reduction of about 8-10% per cycle is typical. This also changes as the rocks begin to shape up and have more efficient surfaces for the stones to work against. Regarding grit and the tumble action - I have tried measuring the effect of the tumble after 4, 5, and 6 days of tumbling, and in reality - the grit has done most of it's work by day 5 from a fresh load, slurry may assist in getting the action going a little earlier, but as very little further reduction occurs after 4 days, there seems no need to do this as the grit breaks down from fresh quite quickly anyway. If you are tumbling softer rocks, then monitor the grit breakdown carefully as this is not always the case. Leave the barrel to stand for 20 minutes before emptying, and leave the bottom dregs of slurry - then rinse under the tap gently, and look for the glittery grit, you'll see quite quickly, how much, and how coarse the grit is, and can adjust the recipe as nescessary. For example - I use 80 grade SiC for week one, but then swap to 220, and run 4 or 5 cycles with the medium grit before the final stages, this gives a much finer and smoother finish, the rough grit can run 2 weeks and still be effective, but the slurry has changed to paste by then and the rocks just bash each other in the barrel!

I don't use other additions, pellets, ceramics etc... as I've never found them particularly beneficial in the early stages, I do however use the plastic pellets in the polish barrel to help cushion the delicate tumbles in the final stages. The crux of the process to my mind is the final grinding stage - I use 400 grade SiC - as it's the finest available here in the UK - but I leave it tumbling in the barrel for at least 2 weeks and preferably 3 without re-charging or interference - this gives the tumbles plenty of time to break down those tiny grains to microscpoic grains, and the resulting stones are smooth and silky - just ready for a wash and on to the polish. Having chipped and damaged 2 batches by trying the burnishing mularkey - I don't bother with this any longer, but I do hand buff the stones with a soft cloth after washing the polish off.

I hope this explains the process a little more clearly - and of course - any queries or questions - please don't hesitate to ask!

Thanks,

Sparkles.