First time with Chrsocolla/Malachite or first stone? This could be
problematic if the latter and a bit tricky if the former.
The green bits are softer than the blue bits and will undercut and
orange peel with most oxides on soft laps. Old rockhounds swear that
using a variety of old worn out sanding discs and finishing with
Chrome Oxide is the key to success, a method I would rather swear
at. Chrome Oxide is filthy stuff and worn sanding discs are hardly
My preferred method is using loose diamond grit for sanding and
polishing on Poly-pads. I have no trouble getting a mirror finish on
Jade, Lapis and other stones that are notorious for undercutting.
Vancouver, Beautiful British Columbia