First tumble progress Nat Geo Pro 3-speed tumbler

Oh, and I already have some new rocks lined up....  here's a test piece I'm working with:



Laser engraving on a sliver of Dragons Blood Jasper, it's probably only 1/16" thick, flattened it out on a 4-sided diamond sharpening stone from Harbor Freight! 

Laser engraving stone is very difficult.   Too much power, and the rock just explodes tiny chips off of it, not enough power, and you get nothing at all.  I think better results would be had if stage 3 were finished and there was a nice smooth surface for the laser.  Can't really see much with the light directly on it with the surface in such a matte sheen.  



Tilted away, the image is more clearly visible.  With it fully polished, the matte area the laser engraved would definitely stand out more.  Also picked up some more amethyst, some labradorite, and an "emerald" that's over 700 carats, but is heavily saturated with green coloring that washes off....  I'll do the labradorite by itself next, then the others after that.  

Half the batch is ready for stage 3, but don't have nearly enough to run it without 2x as much filler.... 

So, I started another batch of rough - forgot again to take before photos   Filled the drum 2/3 full with mostly larger rocks (compared to a small drum anyway) - about 2/3 of which ranged from 1" to 1.5"  x 1.5" to 2" added a few more yard rocks, and some of the smaller rocks from 1st batch that needed more time in the coarse grit.   Added about 2.5oz each of 36 grit & 60 grit SiC and added water to about 1" from top of drum. 

Some of these were cut rocks, some were broken, some are naturally worn.   Total weight of the drum ended up weighing 3lbs 15.2oz, which doesn't seem to bother the base unit.   Anyway, I ran it on highest speed for 2 days, and there's absolutely zero grit left  I can usually feel grit down to about 800 grit size, but nada.  SiC 36 grit was purchased from MJR Tumblers, the SiC 60 grit from Sackorange - both through Amazon.  

I realize Silicon Carbide breaks down because it's quite brittle, but to go from 36/60 to ultra fine powder in 2 days seems pretty extreme....  Going to try again with soap to create the foam I made during step 2, and see if that makes a difference.

There was significant wear & rounding during those 2 days btw... empty drum with just the rocks before tumble was 3lb 0.8oz, after wash off & dry 2lb 4.9oz.   With the additional added rocks, it's back to 2lb 15.6oz before adding grit, water, lid.

Got a set of filter screens coming today for 5gal bucket, they filter all the way down to 60mesh/254 micron, but I also have a 100 mesh/150 micron screen and sifter screens that go down to 25 micron, so I'll be able to capture almost all of the used grit & see just how small it became!