Good Day All
I purchased a large ruby-zoisite crystal carbuncle a few years back
and have just got around to cutting cabs out of a slice of it. Just
purchased the equipment to cut and cab it. So to say the least I am
new to the cabbing field. Probably not the easiest material to start
with. The ruby part is about 88mm wide, the zoisite outer layer is
about 22mm and the whole is about 130mm long and it weights 8 pounds.
Looks like someone cut the top off a stalactite so it's triangular.
I have cut two cabs out of it. The first is half ruby, half zoisite.
have search on orchid and there is a post from few years back talking
about Ruby Zoisite but it deals with trouble polishing the zoisite.
That doesn't seem to be a problem for me. Zoisite polished well.
I worked the first in a classic oval through, 260, 600, 1200, 3000,
14000, 50000 diamond grit. The 260 through 3000 on Doug Klein's
Eastwind Lapidary Diamond 8 inch flat lap diamond disks. (These disks
The 14000, 50000 on a flat lap made from sanded plywood with diamond
I had some chipping on the roughing out on the 260 with the first
one, but it cleared up nicely on the 600.
I worked slow and easy and took my time. It came out fantastic. The
zoisite and ruby polished up to look like waterglass. Total Bling.
The ruby has shimmer and stars showing all over it when in the sun
and you move it through its curve. It also appears to have a totally
clear section running through it 10mm wide.
The second one was cut from the same piece right ontop each other so
they are sisters. This one just doesn't have the zoisite. I cut it
It chipped on the roughing on the 260 and kept chipping and pitting
from there.This cab is cut to the shape of a claw or fang, long and
narrow. All this pitting and chipping confused me because the first
one came out so well.
I have studied the mother crystal and it looks like the 6 pie
sections of the ruby have a very obvious grain to it. The first cab
was cut with the grain and the second against the grain.
I have search the web looking for answerers to my chipping problem.
No luck. I am a member of a lapidary club and the consensus is that I
either cover the ruby in epoxy to hide the chips and pits or just
live with it because that is the nature of the material. I have also
been told to polish it on a copper plate using diamond. This from the
faceters in the club.
That doesn't work of me. I have looked at other ruby-zoisite cabs on
the web and most appear pitted in some form but not all, some are as
smooth and shiny as my first one.
I know Orchid is mainly a metals-jewelry form, but I was hopping
there is someone out there with experience dealing with this type of
I think it has to do with the direction of the cut versus the
direction of the grain.But what do I know, I am new to all this and
those are my observations.I am not willing to continue cutting it
till I have an informed direction, or at least a hint of what might
be happening with this second cab and it pits and chips.
Oh ya one more thing I took a slice off the tip to look at the
mother from top and bottom and there is a totally red clear crystal
rod that is about 10mm wide running right through the middle of the
mother. It is transparent as far as I can tell. I shot a lazar though
it and it shined out the other end and the two cabs have a portion of
this crystal attached to it and it's clear. Should I try and isolate
this area as something special?