Edited and Published by Hale Sweeny
Web Site:
Associate Editors: Geo. Butts, JR Shroeder, Steve Henegar,
Margaret Malm, Sam Todaro, and Ed Elam

This list digest contains the following message subjects:

1. LapDigest News for Issue No. 286 - Sun 3/4/2001
2. NEW: Polishing Glass/Obsidian on Vibrating Tumbler
3. NEW: Will Sanding Silver Hurt My Lapidary Wheels?
4. NEW: How to Polish Black Onyx?
5. NEW: Information on Shahuckite (or Shattuckite?)
6. NEW: How to Cut a Preform for a Sphere Machine
7. NEW: Need Address for Conservation Materials Ltd.
8. RE: Source for K-20 Fire Brick
9. RE: Source for K-20 Fire Brick
10. RE: How to Clean Spots from a Crystal
11. RE: How to Clean Spots from a Crystal
12. RE: Best Foredom for Carving?
13. RE: Need Advice on Restoring Old Viking Tumbler
14. BIO: Trevor Berry
15. FS: Books on How-to-build Lapidary Equipment


Subject: LapDigest News for Issue No. 286 - Sun 3/4/2001

Received a note from Walter Bowser <>,
who is planning a mineral hunting/camping trip into Nepal.
He is providing all camping gear plus airfare. Trip is 11
days and will probably be late August or September. Write
Walt if interested, or interested in a rockhound trip to
Mexico or China.

Not much news this week. I hope you all (or, more properly,
y'all) have a great week. Hug the ones you love and tell
'em that you do. You can't do that often enough!


Subject: NEW: Polishing Glass/Obsidian on Vibrating Tumbler

Congratulations on getting the Digest back up and running.
I missed it back there.

One of our members has a question for the Digest:

"How do you polish preformed glass and/or obsidian in a
vibrating tumbler?

John Bowden

Subject: NEW: Will Sanding Silver Hurt My Lapidary Wheels?

I recently made a knife handle of fossil bone and jade with
silver accents. After gluing the pieces together and
grinding it into shape, I began to wonder if I might be
damaging the grinding wheels. I know that brass will clog
up a standard grinding wheel, but will silver (one row down
on the periodic table) do the same to a diamond wheel?

Should I work on disposable belts instead?


Subject: NEW: How to Polish Black Onyx?

Dear Friends,

I am carving a blue chalcedony and black onyx compliment
each other in a brooch jewellery. Blue chalcedony is easily
polished with cerium oxide and diamond slurry mixture (maybe
you experts will not agree with this but I found out that
if I mix a tiny amount of diamond powder to my cerium oxide
or dab a little on the ultralap I am using, my polish turns
out better).

But could anybody give me an idea how to polish black onyx?

Kind regards from Turkey,

Oya Borahan

Subject: NEW: Information on Shahuckite (or Shattuckite?)

I am looking for information about Shahuckite. Have you
ever heard of it? I have about 100 pounds of rough from
Africa. It comes in a beautiful electric blue and a very
nice pale green. Do you know what it sells for or where I
could get more information.

Thank you
SU: I did a fairly thorough search for 'Shahuckite' and
found nothing in any of my references, in our Archives, or
on the Web. But I noticed that the mineral 'Shattuckite'
is also blue and wonder whether you misspelled or misread
its name. There is lots of info on Shattuckite available,
but possibly not lapidary information. Can you check the
spelling, and let us know which spelling you think is

Is your material in massive form or as a coating on a host
rock? Do you know whether it is hard enough to take a
polish? I would like to see some lapidary properties for
this material - how to grind, sand and polish. hale

Subject: NEW: How to Cut a Preform for a Sphere Machine

I am looking for information on how to preform a sphere
from a rough piece. You cannot always cut to a perfect
cube unless you want to lose a lot of material. Are there
instructions anywhere as to how to cut your material to get
the biggest size sphere.

I have recently purchased some material and have a piece
which is at least 2-3/4" in all directions but it is
pretty irregular. I do not want to waste any more than
necessary, so please help. Any links or instructions will
be greatly appreciated

Thanks, folks, and happy rockhounding.

Robert Redden

Subject: NEW: Need Address for Conservation Materials Ltd.

Does anyone know the current phone and/or fax numbers and
email address Conservation Materials Ltd. Sparks, Nevada,
USA? I have a phone number but it is not in use anymore.



Subject: RE: Source for K-20 Fire Brick

You can get the fire brick and related soldering blocks from

"Bourget Jewelry Crafts and Supplies" in Santa Monica
California. The Fire Brick, catalog # 54-244, is listed as
$4.80 and my catalog shows a sale price of $4.30.

This is where I got mine. Their main catalog has the listing
even though their website does not show it. Emailed them at
<>, call them at 800-828-3024 and see
their website at <>.

Ernie Ogren
The Geode Man

Subject: RE: Source for K-20 Fire Brick

Also try Thermal Ceramics Augusta Georgia 800 796 4326

Bob Aurelius

Subject: RE: How to Clean Spots from a Crystal

Hi Karen

Saw your question on Lap Digest - here's a link which may

Not sure what you mean by silica spots, but most (many)
crystals - especially quartz - has a coating of iron oxide
(reddish stuff). The procedure described here works well
for that. It also works for other types of grime. You can
buy Oxalic Acid at most hardware stores under the moniker
"wood bleach" (Home Depot does not carry it). Also,
muriatic acid cleans off calcium deposits, clay, and
others; just be careful. Dilute it and let it sit 'till
clean. Don't mix with oxalic!

Make sure you test your crystal with each acid before
immersing the whole thing. Depending on what you have the
acid could "clean" the whole crystal away to nothing but
sludge (muriatic does a great job of destroying beautiful
calcite crystals, and Oxalic ain't too kind to any iron
based mineral)

Good luck


Subject: RE: How to Clean Spots from a Crystal

<<Can someone tell me how to remove silica spots from
crystals? Both inside the tiny cracks and out.>>

Oxalic Acid can be obtained from your hardware store in the
section for cleaning bricks or sold as Wood Bleach. It comes
in small white crystals. Make up the acid solution by adding
about a 1/2 cup to 1 cup of Oxalic Acid crystals into a
bucket 1/2 full of water. Stir up. Add your crystal and
allow to soak. This will take at least 1/2 day and maybe
all day. Remove and rinse like before. If you mildly heat
it, it will work better, outside ventilated. Even if the
procedure fails to clean the material, your rough will not
be damaged as this material will not attack tourmalines,
aquas or even quartz. You can reuse the solution many times.
For disposal you must neutralize the liquid.

To get rid of rust, try Naval Jelly; just paint it on and
wash it off. Or try Iron-out, which is sold in Grocery
stores. Iron-out, as purchased, is a white powder. If you
want to clean topaz or quartz, get some plastic buckets or
containers. Add about 1 tablespoon of Iron Out per pint of
warm water. Put rocks in Iron Out solution for about 1-2
hours. When done, pour liquid down drain and rinse

Cleaning calcite Muriatic Acid Baths

Supplies: You will need a bottle of muriatic acid (sold for
pool cleaning or concrete etching), a couple big boxes of
Arm & Hammer baking soda, plastic buckets or containers,
rubber gloves, and chemical splash goggles.

Procedure: Fill one bucket with crystals to treat. Add
water until level is 1/3 or so full. Carefully pour in
approximately 2 cups of acid. (Never add water to acid!!!
Always add acid to water) Fill another bucket with water
for rinsing and finally another 2 buckets with water and a
cup or two of baking soda. Keep an empty bucket on the

If you have calcite, it will start fizzing immediately.
Allow it to continue fizzing until it stops. Pour off acid
into empty bucket. Pick out a sample crystal or two with
your rubber gloves. Dip in water then into a baking soda
bucket. Examine them. If they are not clean, you can pour
the acid water back on them and add some fresh acid. Repeat
until clean. This will not work on lepidolite though, only
calcite. After you are done, rinse all crystals in water
and let sit in baking soda for a day or so to completely
neutralize all acid. To dispose of acid, add baking soda
to neutralize. Pour down drain with excess water. This
should take you 1/2 day at most. If you splash acid on
yourself, rinse with baking soda water, and follow with

Sometimes your stain is not a stain, but is a skin of the
same material. This is professional stuff only, but you can
try ammonium bifluorite (HF acid) which attacks Quartz.
Before attempting read very carefully: The Care and
Conservation of Geological Material: Minerals, Rocks,
Meteorites and Lunar Finds, Frank M. Howie, editor.
Published by Butterworth-Heinemann 1992.

Lastly you can physically remove coatings, a flex shaft with
wire brush, or sandpaper, tiny grinders or even miniature
impact hammers to chisel. A good way to preserve the shape
is to use a mini-sandblaster with various abrasives. There
are even hi-pressure water jets designed to clean minerals.

Aurora Minerals,
679 S.Ocean Ave.
is a good source for abrasives.

Crystal Mark Inc.
613 Justin Avenue
Glendale, California 91201

Mark Liccini
Also see:
by John Betts. It is a mini-treatise on crystal cleaning.

Subject: RE: Best Foredom for Carving?

<<For a beginner at carving, which is the best Foredom tool?
There are two kits: 2272 with handpiece #30 and kit 2273
with handpiece #44T.>>

Hi Gail,

I'm not a carver, but have used several models of Foredom
flexshafts and handpieces. For my money the best motor to
get is the 'R' series. It has a feedback circuit built in
and provides almost full power at low speeds; the rest tend
to be lacking in power at slow speeds. I've not used the
1/4 hp unit, it may not suffer from lack of power at slow

If you use predominately 1/32" diameter bits, & change
them frequently, a quick change handpiece will save lots
of time. It'll take some of the tedium out of carving. If
it were me, I'd opt for the Tecno-X handpiece, I don't think
it's made by Foredom, but it fits all standards flexshafts.
IMHO it's a better quality unit than the Foredom units.

If money is no object, you might consider the micro motor
or high speed pneumatic units.


Subject: RE: Need Advice on Restoring Old Viking Tumbler

I also recently found an old VT-14 Vibro sonic Tumbler in
need of repair including belts. Originally these tumblers
were produced by Geode Industries in New London, Iowa but
are now produced by Custom Technology Ltd. New London, Iowa
52645. Tel. 319-367-2256, They also have a web page at

These people were very accommodating and I have my unit up
and running and am very pleased with it.

Hope this helps,

Bill Sweetman

Subject: BIO: Trevor Berry

Gday Folks,

Let me introduce myself: I am Trevor Berry and the owner
of Berryd Opals (web site: I sell
on behalf of the opal miners of Coober Pedy and surrounding

I have been a member of the Lapidary digest for about 1
year and was put on to the digest by one of my customers. I
have read a lot about the cutting of all sorts of material
and I have found it interesting to compare the articles to
the process we use for opals.

I was taught the art of opal cutting at TAFE, Coober Pedy,
an adult education facility that teaches all there is to
know within the opal industry. I have been fortunate enough
to be asked to assist within the cutting class. The cutting
aspect included Solids, Doublets, Triplets, Carving, Inlay,
Faceting and beading of Opal. The course is open to
international as well as Australian students.

Apart from, my ability to supply rough opal to you, I am
also available to answer any questions one might have about
opal. If I do not have the answers I have the contacts to
attempt to help you.

Feel free to email me at .


Subject: FS: Books on How-to-build Lapidary Equipment

Many people are becoming interested in lapidary work but
can't afford the equipment to follow through. I have written
a set of 3 books to help with this. They are entitled
(1) Build Your Own Swing Arm Slab Saw (l9 pages)
(2) Build Your Own Cabochon Maker (19 pages)
(3) Build your Own Angle-Head Cabochon Sander (13 pages).
They have soft covers, are 8-1/2" X 11" in size, with photos
and many diagrams with dimensions. They are professionally
printed and are written with the novice builder in mind.

I have built and used these machines many hours and know
they work well. These are not faceting machines but are
designed to make beautiful cabochons from raw material. I
have been a rockhound and doing lapidary work for at least
the last 30 years. It's a thrill to find a stone in the
desert or stream and turn it into a thing of beauty. You
can do that with this set of books and a little work. I
am selling them for $29.50 a set (add $2.50 for shipping).

Otto Laube
If any of you have a set, please write up a review of these
three books for publication in the Digest; I'd like to push
'build it yourself' lapidary equipment as a way for more
people to get into lapidary! hale
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