VEVOR KD-B1031 Mode D'emploi page 25

texture should never be used as tumbling rough.
Good tumbling rough will consist only of rocks with a smooth,
non-granular texture, When the rocks are broken the surfaces should be
smooth to the touch.
You can probably tell if the texture is suitable just by looking at the rock and
checking for any visible granularity. A good tumbling rock will be
microcrystalline with no visible grains. Another good way to tell is to rub the
rocks together and see if any small grains are produced. lf not, then the
texture is probably suitable.
If you attempt to tumble a rock with a gritty or granular texture then you're
going to end up with bad results. The rock will disintegrate into little bits of
grit which will destroy every other rock in the barrel. Those bits of grit will
act just like the tumbling grit you add in each step, except they are the
wrong size so they'll just scratch everything up and leave it looking dull.
High Density
It's important not to add any porous rocks to your tumbling rough because
those pores make for perfect little traps for tumbling grit. lf you put these
rocks with pores, voids, or pits into your batch of tumbling rocks you
probably won't notice any problems in the first or second cycles, but you'll
definitely run into problems in the pre-polish, polish, and burnishing stages.
The problem is that the pores trap grit from each step and carry it on to the
next steps. lf even a few pieces of larger grit make it into the polishing
stage then you'll end up getting unsightly gouges in your otherwise nicely
polished rocks. There is almost no amount of rinsing or cleaning you can
do avoid this carryover of grit if your rock has a bunch of pores, so it's best
just to avoid them entirely.
Lack of Fractures
It's important to check over your tumbling rough for any rocks that have
noticeable fractures. lf you find any rocks that have visible cracks or
fractures make sure to remove them from the batch.Or, even better you
can break those rocks up along the fractures and tumble the pieces.
Tip: Breakup any fractured rocks along their visible fractures before
- 24 -