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This list digest contains the following message subjects:

1. LapDigest News for Issue No. 293 - Wed 4/25/2001
2. NEW: Hillquist Saw Repair or Spare Parts
3. NEW: Making Opal Mosaic Cabs
4. RE: Sphere Preform Cutting Jig
5. RE: How to Make Beads
6. RE: How to Make Beads
7. RE: How to Make Beads
8. RE: How to Make Beads
9. RE: Stability of Peruvian Blue Opal
10. RE: Stability of Peruvian Blue Opal
11. RE: Flexible Shaft Tools for Opal Carving
12. RE: How to Dye Coral
13. RE: How to Dye Coral
14. RE: Cabbing with a Faceting Machine
15. RE: Cabbing with a Faceting Machine
16. RE: Cabbing with a Faceting Machine
17. RE: Cabbing with a Faceting Machine
18. RE: Cabbing with a Faceting Machine
19. RE: Enhydro Quartz
20. WTB: Traditional Western Rough


Subject: LapDigest News for Issue No. 293 - Wed 4/25/2001

Y'all should know how I feel about making lapidary equipment
by now, so you will understand how happy I was to get the
following note from Kreigh: "My plans were for a liter (or
maybe a gallon) barrel, and Bruce Mitchell used them to make
a 45 degree tumbler with a 5 gallon drywall bucket barrel!
You've got to see this industrial strength tumbler:

My hat's off to Bruce Mitchell! Kreigh Tomaszewski"

My hat would be off, too, if I owned a hat!!! It is worth
a look!!!

Our membership is now about 2600!!!

I'll keep this short as we have a large number of items in
this issue. Enjoy this beautiful spring weather!!


Subject: NEW: Hillquist Saw Repair or Spare Parts

I have a 14 inch Hillquist saw that has a very neat drive
mechanism that drives the rock forward into the blade. It
uses a kind of clutch which slips when the rock offers more
resistance (because it is bigger or harder) and so drives
it forward more slowly. This seems quite ingenious to me.
Well, this saw has not been made in many years and so I
can't find either a part or a person who knows how to fix
this clutch, because, yes, this klutz broke the clutch.

The clutch consists of an outer piece shaped like a brake
drum and 3 Bakelite (?) spokes with a piece of metal
inserted into them each of which reaches out and grabs the
inside of the drum and, by friction turns it. Well, it
stopped turning it. I took it apart and was going to
remove the oil and roughen the inside of the drum, which I
still will do, after I glue the Bakelite and metal piece
back together OR after I get one from some kind reader who
happens to have one.

Anybody able to help, with either a piece or a whole
assembly or helpful instructions or even a kind word?

Thanks in advance.


Subject: NEW: Making Opal Mosaic Cabs

I'm looking for some information about cabbing. I have
several very small pieces of opal, and I'd like to make a
large cabochon from these, as a mosaic. What is the best
way to make a mosaic cab from small pieces of opal?

I think it won't be simple, but I want to give a try.


Peter Drummen
Wonderful question!! We have not had a thread on how to make
mosaics from small pieces of opal before, and I look forward
to this discussion. hale

Subject: RE: Sphere Preform Cutting Jig

<<Does anyone know where I can buy a Sphere jig preform for
my 24 inch saw. This jigs allows one to accurately cut the
"blank" for the sphere machine.>>

Richardson's makes one. Their phone number is 541 475-2680

Tim Fisher
See naked fish and rocks!

Subject: RE: How to Make Beads

<<Thought I might drill holes and then tumble them, or
tumble then drill?>>

My bead mill just came in the mail last week (thank you,
eBay), so I too am eager to make some beads. I have a
few questions and plans I would like to discuss.

Let's start with making cubes. Does anyone make them in
mass quantities? My mill's polishing parts are defunct, so
I'll need a tumbler full before I can finish them. My plan
is to glue slabs together with waterglass and saw through
the stack. I would then glue those "slabs" together and
saw in the third direction. A water soak would liberate
cubes by the hundred.

As far as preforming the spheres, why NOT use a tumbler?
Rotating tumblers take rough stones and grind the points
off, which sounds like just the thing to get cubes ready
for the mill. What am I missing?

Flint Smith

Subject: RE: How to Make Beads


Do you want round beads or just beads that are rounded off?
If you want beads that are just rounded off just put your
cubes in a tumbler with enough other material to make up a
full batch and tumble them with the rough grit until they
are the roundness you wish.

If you want round beads there are three ways to get there.
The first is to grind the cubes corners off and then begin
to round them the best you can. Once they are about round
use an old aluminum template and rub each in a hole a bit
smaller than the bead preform. The aluminum will mark the
high parts of the preform. Use a grinder to remove the
marked areas. Continue marking and grinding until the beads
are formed. Use finer grits of wheel as the beads become
rounder. Polish when final rounding and sanding has been

The second way is to predrill the cubes. Drill as near the
center as possible. Once the holes are in the cubes begin
rounding the corners. When some roundness is acquired put
the preform on a stiff steel peg mounted in the end of a
wood dowel and begin final rounding of the beads. Work on
one end then the other allowing the bead to spin on the
steel pin. When the grinding and sanding is complete
polish and string.

The third way is to use a bead mill. Roughly round your
cubes as in the other methods then put them in a bead
making mill. Grind with a coarse grit until all beads are
rounded and no flat spots are present. This may take some
close inspection to make sure all the flats are removed.

If you use a bead mill I can send an article in preparation
that is being written on making beads in a bead mill.

Let me know if you need any additional info.

Wayne, there is a fourth way which is kinda neat. Make a
holding tool from a dowel with a cup on the end which is
bigger than the bead you want to make. I make my cup tool by
taking a dowel piece and forming steel epoxy in a glob on
one end around the dowel. Then find a wooden ball about
1-1/2 times bigger that the bead you want to make, and push
the ball about 5/8 of the ball diameter into the end of the
glob. (I drive a brad into the ball so I will have something
to pull it out with. I first spray the ball with WD-40 so it
will release easily.) Let the epoxy cure. When half-cured,
you may trim the excess epoxy away with a knife. In use,
grind the cube into a rough ball shape, and put it into the
cup. Hold the tool to the grinding wheel so that the handle
is downward and at an outward angle, and the ball will start
spinning and grinding away the high spots. When it is round,
move to the next wheel, etc and finally to polish. That is
my favorite way to make marbles. (See the next letter for
a neat way to improve this method)

In Wayne's second way above, you are not limited to round
beads. Using the same method and tool, you can make tubular
beads, rondels, etc. hale

Subject: RE: How to Make Beads

Hey all,
A quick note on making beads. Actually this is marble
making, then you can make them into beads. First rough
grind the cubes on a 200 grit SiC wheel (my preference).
Then take a wooden dowel about twice the size of the
finished bead with a rounded depression (twice the diameter
of the bead) in one end, put the rough pre-form in it and
hold it gently to the 200 grit wheel to shape it. You will
need the finger out of an old glove to wear while you put
some drag on the bead, this helps the bead drag against the
wheel and cause the grinding action, rather than just
spinning against the wheel. You could do this through all
the grits but, I prefer to just dump them into my next
tumbler load. Relatively simple, but does require some
practice and a good pre-form.

Hope this helps.

Randy Glenn

Subject: RE: How to Make Beads

To Mary Jane

A lot has been written about bead making and in all of it
you will discover many different procedures, opinions and

From my experience, I would suggest you not drill the cubes
before making the beads. The hole tends to accumulate
grit/polish and sometimes will cause a flat area to develop
around the hole. Its kind of a chicken and the egg thing..
its easier to drill the cube but you get nicer results if
you drill the finished bead.

There is a nice little book that explains how to prepare the
cubes and create beads called, "Specialized Gem Cutting",
by Jack R. Cox. I believe the Lapidary Journal Book Shop
has it. Another very helpful little book is, "Marble
Making and Lapidary Hints" , by Red and Ann Wilson and
printed by the Western Printing Co of Lubbock, TX.

Re tumbling the beads, that is an option with some stones.
It depends on the material (hardness, whether it undercuts,
etc). But again, I would not drill until after your process
is completed. Rio and other suppliers have bead (or pearl)
devices to hold the bead steady for drilling if that is a


Subject: RE: Stability of Peruvian Blue Opal

Kaiser -

I've cut quite a bit of the Peruvian opal since it first
came on the market about 9 or 10 years back. It is very
sensitive to heating. I've had cabs which were almost
transparent blue go to a totally opaque milky green in the
polishing step because they got too warm. Could heat be your
problem? How were/are you sawing the material? This is my
best guess based on cutting a few pounds over the years.

Jim Small
Small Wonders

Subject: RE: Stability of Peruvian Blue Opal

I have had some success with the method to be described.
Not all opal is treatable.

I bought a small hand-operated pressure/vacuum pump from
Cole-Parmer, Model 79301-10. It has a gauge which shows
either vacuum or pressure. It also has a switch to change
from vacuum to pressure. A semi-rigid hose was attached to
the pump and to a heavy glass jar with a metal lid using
things from the local hardware store. An airtight metal
container will also work. The other thing needed is also
from the hardware store. It is a clear glue curable with
ultraviolet light. The glue was designed to provide
invisible mends for glassware. Glass and opal have similar
refractive indices. The one I have used is Duro Clear Glass
Adhesive #CGA1 81190.

The process must be carried out in dim light. Opals which
have been taken to prepolish stage and dried are coated
with the glue and placed in the chamber. I draw about as
much vacuum as the pump can provide and leave the vacuum
on overnight. Then the vacuum is released slowly. Pressure
is then applied. The pressure is held on for about twelve
hours. Pressure is released from the chamber. The opals
are cleaned of excess glue on the surface. Either isopropyl
alcohol or acetone can be used. I prefer the alcohol because
it seems less aggressive. The stones are then exposed to
ultraviolet light. Here in Arizona that's easy to do with
sunlight. After the glue is cured, the opals can then be
given the final polish.

I hope this will work on the Peruvian opals.

Ivan Saddler
For info on the hand pump referred to above, see the website
=7930110&cat=1&sel=7930110 hale

Subject: RE: Flexible Shaft Tools for Opal Carving

<< Another product I like from Hi-Tech diamond is their
extensive line of diamond compound in a syringe. They mix
diamond grit with a toothpaste like material. You squirt
very small amounts on a felt bob and start polishing. You
cannot use this stuff with opal since it must be worked
dry and will heat the opal too much. ...(snip)...>>

Hi-Tech's diamond compound will work very well with opal;
just add a drop of extender fluid after you put the
compound on the felt. When they say work it dry they mean
don't use water. I have had good luck with it on most all
the materials I carve except turquoise and jade. I have
better luck with aluminum oxide with them.

I use felt with grits 3000 and finer. I need a firmer
backing with the courser grits. I have had to make my own
wheels for the courser grits.

Dick Friesen

Subject: RE: How to Dye Coral

Hi Hale
In answer to the question on how to dye coral: I have had
very good results by adding RIT cloth dye to denatured
alcohol. Put your slabs or stones in and let set until
It absorbs to the depth of color you want.


Subject: RE: How to Dye Coral

Rain and Sam,

To dye coral, the artists in Asia use a simple aniline type
dye mixed with alcohol. (You can also use this on some
agates!) They usually use it to enhance the color of coral
that already has some natural color rather than trying to
make white or pithy coral another color. The problem is the
dye colors any cracks or porous areas darker than the solid
areas giving it a mottled look. If that is not important,
perhaps you could cut out the more solid areas for what you
want to make. Use pink or coral color dye and you might
even mix some colors yourself. Let the coral soak for
several days, then wash in mild detergent and allow to dry.
You will have to experiment with the colors and soaking as
every piece of coral will react differently. hen finished,
polish the solid pieces with ZAM on a muslin buff.

I have also used Tidy Bowl toilet cleaner to dye very
porous coral when making beads. It is quite permanent to
the best of my knowledge and presents a nice blue result.



Subject: RE: Cabbing with a Faceting Machine

I also have a Graves Mark IV, and I regularly use it as a
flat lap. Remember, a faceting machine is just a flat lap
with a tower and machinist controls for indexing angles.
Anything you can do with a flat lap, you can do with a
faceting machine. It is also perfect for backs of all my
opals, no matter what I grind them with.

I did change the pulley size to speed up the rpm on the lap.
After a few faceting classes, I got bored. I am too
impatient, I guess; I like faster results.

Jack Parker
Blue Bell, PA

Subject: RE: Cabbing with a Faceting Machine

That is generally what I use to cut opals. The variable
speed is nice; I have a LEE faceter. Stick to no lower
than 600 grit and preferably a worn one; the more
vibrations, the more risk of cracking the stones as I
understand it. After grinding with a 1200 grit, I use wet
sandpaper disks of 1200 grit (600 first if I need to) glued
to a dense foam rubber backing on a lap(the kind of foam
they use for sitting on in cold weather, for example).
Finally, I use cerium oxide on leather to polish them.

A little tip for doping: If you want to hot dop an opal and
have one of the light bulb heated wax pots, put a small
piece of paper towel down first under the opal piece.
It slows the heating process of the stone.

Jeanne Moen
Art of Stone
Kristiansand, Norway

Subject: RE: Cabbing with a Faceting Machine

In response to the question about horizontal cabbing. Thirty
or more years ago several manufacturers made horizontal
cabbing units - Covington, Hillquist, Gemlap and B&I. They
offered 8" & 10" models. These units did horizontal sawing
and grinding and sanding and polishing. The B&I even
offered a faceting attachment.

We have done a lot of flat lapping on our own Graves Mark I.
To cab you hold a dopped stone vertically. Use a rolling
motion while your wrists rest on the edge of the pan. If
you are handy you can make a grooved lap of 1/2" phenolic.
The grooves can be shaped like those on the spool polisher
sold by Graves. Charge them with various diamond compounds
to help control sanding the curve on the cab.

Speaking of Graves, they also sell a thing called Star Cup
which screws onto the spindle of a Facet machine or vertical
arbor. The copper and lead cups can be charged with
diamond to sand and polish high domed stones like Idaho star
garnets or star rubies/sapphires.

Hope this helps.

Bob Edgar

Subject: RE: Cabbing with a Faceting Machine

Cabbing with a faceting machine is sometimes easier, except
you have to change laps as opposed to using a Genie. I
purchased 5 Lucite cabbing laps for various grits and they
worked fantastic... until they became contaminated. I have
pinched nerves and holding a dopped cab to a Genie wheel is
irritating to my hands and doing it on a cab lap is much
easier on me and since it is curved I get better domes for
less work. I have used flat laps for cabbing but it is
almost as much work as it is on a Genie, but my wrists are
in a better position so I think it is better on a faceting
machine regardless of the laps you use.

That is my experience with cabbing on a faceting lap.

Jill Rowlands

Subject: RE: Cabbing with a Faceting Machine

I often use my Raytec Shaw faceting machine to cut round
cabs. It is perfect for that function, but the Graves
should work about the same.

When using the round template to draw my trace, I use the
quadrant marks to mark the center of the stone. I do a
rough-out on the saw then pre-form as close to the trace as
possible with either the saw or on my grinder. Next I place
a large round head dop in the bottom part of my Raytec jig,
heat the stone and place it on the dop with the center mark
up. Prepare another round head dop of sufficient size with
dop wax. Put a pinpoint dop into the top of the jig, drop
it down and center it on the center mark. Now heat the wax
on the second round head dop, carefully replace the pinpoint
dop with the waxed dop and push it down onto the stone. Let
it cool for a few seconds then pick up the entire jig while
continuing to push the top dop onto the stone. Now hold the
dops and stone over the alcohol flame until the wax 'fairs'
between the dop and the stone.

Let it cool and place it into the quill. Lock out the index
trigger, set the protractor at 90 deg and drop the tang
table or facet head down until the lowest point on the stone
is just resting on the lap. Round the stone out by turning
the index gear by hand (or with the preformer if you have
one). When the stone is round, begin cabbing it by working
up the protractor 10 deg at a time till it is at about 10
deg from 0. Then work back down again, turning it
constantly. By the time you return to 80 deg, you should
have a nicely formed and true round cab.

Now take it out of the quill and finish it on the fine
grinder, smoothing wheels and then polish.

If you are not cutting rounds, there is no reason why you
cannot cut hand held cabs of whatever shape on the Graves
8" laps. Just be careful not to dish or gouge the wheels.
Use a light hand. You probably will have to make up some
rubber backed laps of Lucite or other material to do your
smoothing etc. I would not use carborundum/si2 on the
faceter as it may leave residue that could transfer to your
faceting/polishing laps. But, as long as you use diamond
compounds/laps for the entire process there should be no
problem and its the same as cabbing on a horizontal machine.
My primary cutting machine is a 30 year old horizontal
machine that I built myself.



Subject: RE: Enhydro Quartz

Hi Hale, At least one contribution for the year! or is it
two years now?>...

For these Geodes there is nearly always a flat bottom inside
the cavity, thus with experience you will find the enhydro
ball to have an entrance or fill point also, carefully look
at the stone and you will see a broken rough or flat looking
area this is the entry point or water fill zone and thus the
flat zone on which to place a window for viewing the liquid.
If you are cutting these for liquid display only then choose
the ones with the broken flat base, once you hit the white
quartz your window is finished.

The internal white quartz layer is always 2mm to 5mm thick
and is normally stable with out fracture, so as long as your
equipment is vibration free, it is simple to lap to a
desired transparency to view the water, Then once you have
done a few you will be able to determine the round ones flat
inside area to cut a window against this also. I
personally prefer the inside of these geodes as cut in half
display pieces as their patterns and crystal structure is
always looking great rather than cutting for to see the
water inside.

I have been obtaining quartz crystal here in Tanzania that
contain water in what appears to be bubbles inside the
quartz crystal, Interestingly these water pockets appear and
disappear with the variation of atmospheric pressures,
unrelated to the above but I found it quite interesting. The
best piece I have in my collection weighs about 1kg and has
21 water bubbles in it.

As a matter of interest can anyone beat that? or has seen
one with more?.

Kindest regards,

TZ-GEMS - Tanzanian based Wholesalers of African Facet
Rough. Mine Direct Source for; Rough,& Natural Crystals.
Tel: +255 22 2121058 Fax: +255 22 2121005

Subject: WTB: Traditional Western Rough

Dear Hale,

Good to see you back "in the saddle". Your services are
much appreciated.

I have been in the gem and jewelry business for the past 32
years and will be semi-retiring soon. I plan to do shows
throughout the West and my emphasis will be custom cabs and
jewelry featuring Western American gemstones. I am always
looking for the better lapidary materials from Western
sources, but am especially interested in getting those old
classics such as Bruneau Jasper, Poppy Jasper, California
Jade (Idocrase), Nipomo Sagenite, Faustite and any of the
classic Nevada Turquoises or Variscites. Actually, any
Western American lapidary rough that is unique will "float
my boat".

I welcome any of you out there who might have materials
that might be of interest to contact me at : or call me at 805 528 6661.


Ron Mills
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