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

This list digest contains the following message subjects:

1. LapDigest News for Issue No. 230 - Mon 9/6/1999
2. NEW: Photosensitive Minerals
3. NEW: New Opal Book by Downing
4. NEW: Motor Speed Control
5. NEW : What Is It?
6. NEW: Opal Treatment for Cracks
7. NEW: Jewelry Making Classes
8. RE: Upgrading from a Cabmate
9. RE: Filling Cracks in Dino Slabs
10. RE: Mystery Stone?
11. Re: Mystic Topaz
12. Re: Mystic Topaz
13. Re: Mystic Topaz
14. RE: Mineral Oil as a Trim Saw Coolant
15. BIO: Doc and Liz McKay
16. WTB: Red Horn Coral Fossils
17. FS: GEM SILICA SALE (with correct URL)
18. FS: Obsidian
19. FS: 18" Slab Saw for Sale
20. FS: Belt sander
21. SHOW: Knoxville, TN


Subject: LapDigest News for Issue No. 230 - Mon 9/6/1999

Well, I am going again tomorrow to Wildacres for a week. My
computer has been acting up yesterday and today; every once
in a while, the machine will lock up and I can't do anything
on it -- Can't even get Ctrl-Alt-Del to work. Only thing to
do is to shut it down and pray that I have saved everything.
Because of this, I am cutting it off while I am gone, and
hopefully my son will have a look at it. Otherwise, when I
return, I'll take it to my favorite Magicians. IT WILL NOT
BE ON FOR THE NEXT WEEK!! Be back next Monday!!

Y'all have fun while I'm gone!!!


Subject: NEW: Photosensitive Minerals

Thanks to everyone for their emails about photosensitive
minerals. In response to your questions, please visit the
"In the Spotlight" link on the Mineral Collecting

After losing some treasured specimens to suspected damage
from light, I did a lot of research. Thanks to several
museum directors/curators and piles of books, magazines and
journal articles, I've managed to compile a list of minerals
that are either known or strongly suspected to be
photosensitive (usually as the result of a scientific study,
controlled-condition experimentation, or museum curator

I hope this article helps answer some of your questions.
And please - if you know of something that is missing from
the list, let me know!


Christopher Leger
Your Guide to Mineral Collecting
Normally, this would be outside the scope of the Digest and
would not be included. But it occurred to me that I had
not seen such a list anywhere before, and that we do cut
strange materials. If you are starting to cut a strange -
to you - material, it might pay to check this list before
you start. hale

Subject: NEW: New Opal Book by Downing

Being an Opal lover and a rough dealer I wanted to pass
this on to the list.

Paul B. Downing, Ph.D. has a new book coming out called
OPAL - Advanced Cutting & Setting

There is a Special Pre-Publication price of $12.95 plus
$4.00 S&H. The regular price of $15.95 starts after
Jan 1, 2000. Shipping is expected by December 15, 1999

Check out the following URL for details
JR & Janet Schroeder
J & J Jewelry

Subject: NEW: Motor Speed Control

Hi Folks -

I have a GE 1/3 HP motor, salvaged from some piece of
electronic gear or other. I want to run a diamond wheel
directly off the shaft, plus other accessories. But the
motor runs at 3,000 RPM, which is fine for some
applications and a mite speedy for others. Is there a cheap
way of improvising a speed control? I have a foot control
for my Foredom, but that uses, I believe, a 1/8 hp motor,
and might burn out if I tried to use it to control the more
powerful one. Or might it? Being electronically illiterate,
I don't know. How about a lamp dimmer? If it's cheap enough,
I don't care if it burns out after five weeks; I'll just
get another. Any advice or suggestions?

Hans Durstling
Moncton, Canada
Freelance writing. Feature stories, technical ad copy,
clear manuals, bid documents, simple english, videos,
speeches. Email for publication and client list.

Subject: NEW : What Is It?

I acquired a large preserving jar filled with what I think
is some sort of polishing compound. It was included with
other known polishing powders such as stannic oxide and
cerium oxide.

The faded label on the jar bore only the legend ... E III

I presume that the three IIIs stand for 3. Nobody at our
mineralogical society has ever come across it. Does
anybody have any ideas as to what it might be ?

Lorna Quinton.

Subject: NEW: Opal Treatment for Cracks

I hope that you will share the secret of fixing cracks in
opals with the readers of LD. I have about 3 ounces that
were in a drawer for several years and a lot of them show
fine cracks that I would like to fix. I had considered
soaking them in "water glass" but have been informed that
is a waste of time and opal.

Some of these opals are from Mexico and have very nice
color if only they did not have cracks. Maybe other readers
have techniques that work also.

Keep up the good work.

Many thanks,


Subject: NEW: Jewelry Making Classes

I am interested in seeing if there are any jewelry making
classes in the Wilmington or near surrounding areas. Also
I am looking for a good, honest source of reasonably good
opal rough. I am located in North Carolina for about 6-8
months and would like to know of any lapidary shops around

I enjoy reading lapidary digest and appreciate finding out
about the mineral Wad and it's location. I bought a couple
of specimens and some cabs that were beautiful. Your digest
has been very helpful and look forward to it each week.

Thanks lots.

Lee Corey

Subject: RE: Upgrading from a Cabmate

Some of you may remember that a while back I chose to
upgrade my Cabmate with a rubber expanding drum and diamond
belts instead of selling it and buying a Genie.

It works fine, and I've cut a handful of stones on it
already. I have one problem that I was hoping someone
might be able to help with.

Getting the belts on and off the drum is very difficult.
They are quite tight, so putting them on requires pushing
with some force around the drum. Taking them off is the
worst part. That requires pinching the belt to grab a spot,
pulling the spot, and repeating over and over. My wife,
who also wants to use this setup, has some pretty bad
arthritis in her thumbs and can't possibly do this motion.
It hurts me and I don't have arthritis! (well, maybe I do,
but I don't have it as bad as she does).

So how about it? Am I doing something the hard way when
there's really an easy way? Should I coat the rubber drum
with grease?


Bob Lombardi W4ATM in Melbourne, FL (ex-WB4EHS) or
Visit the ATM's Resource List-
Or visit me at

Subject: RE: Filling Cracks in Dino Slabs

Filling cracks in Dino bone or anything else, try a product
called Ceramit. It comes in many colors and cures by time
or by heating. Alpha Supply of Bremerton WA is a good source.


Subject: RE: Mystery Stone?

To Randy Aue--
The black/white/ruby red material you have may be Eudialyte
a pretty (sometimes with flower-like patterns) material
from Alaska.

Vi Jones

Subject: Re: Mystic Topaz

<<<snip>It is called "Mystic Topaz" and looks like a piece
of fine "Carnival Glass". She re-cut a nick on the culet
and the cleavage plane was in evidence. She also said that
the refractive index was 1.62. The Brazilian who sold it to
her said that the cut stone is taken to an almost melting
point and then bombarded with radiation containing gold and
another mineral element. This is supposed to impregnate the
Topaz and give it highly refractive appearance <snip> He
stated that the process was so expensive that no more than
this first production will be forth coming, at least in the
near future.>>

Hi Terri,

I haven't seen any "Mystic Topaz" but have no reason to
believe that it isn't Topaz. Topaz has a refractive index
range of from 1.61 to 1.63. The part I have trouble
believing is the radiation part. I used to be in the stained
glass business. Among other processes applied to the glass
one was a technique called "lustering" (also used frequently
in china painting). A suspension of different chemical
compounds is held in a flux which is painted or sprayed onto
the glass.

The glass is then fired in a kiln to just below the melting
point. The chemicals fuse & react with the surface of the
glass to give the finish you describe. A few years ago a
very similar process was tried quite successfully on quartz

A similar process was also used on white or light colored
sapphires to simulate top color stones. The problem with
the process is that the layer of luster is only on the top
surface of the material so treated. If you just want a
display peace to set on the shelf they are great. The luster
will last practically forever.

However if you want to cut the stone, my guess is you will
end up with a nice but colorless piece of topaz.


Subject: Re: Mystic Topaz

<<The Brazilian who sold it to her said that the cut stone
is taken to an almost melting point and then bombarded with
radiation containing gold and another mineral element. This
is supposed to impregnate the Topaz and give it highly
refractive appearance - rainbows everywhere. He stated that
the process was so expensive that no more than this first
production will be forth coming, at least in the near


My partner, Al Watkins of Crystal Essence in Arizona, uses
such a stone. The one he sells is called "aqua aura,"
though I suspect the treatment is the same. According to
him, the stone is heat treated in a vacuum chamber, then
gold and titanium are applied. I do not know the exact
process. However, I do know that radiation cannot carry
molecules of a metal with it. When you change a substance
by irradiating it, you are bombarding it with subatomic
particles (alpha and beta) or, more commonly, gamma rays
(which do not have a particle component).

I can send you paragraphs from my Radiological Monitoring
Handbook if you want more detail. This does not mean, of
course, that irradiation is not somehow part of the process.
Perhaps the individual lost something in translation, or
did not fully understand the treatment. In any case, I
wonder about the comment concerning the expense.

The stone "aqua aura," and other similarly treated
iridescent "carnival glass" stone, is common. Perhaps
someone experimented with topaz and found it is much more
difficult to treat than other stones used as a base for the
process. I have raised a few questions, but I also hope I
have answered some of yours.

Don Halterman
(de-lurking 1st time)
As I understand it, in making 'aqua aura', gold or other
metals are "sputtered" onto the piece; sputtering is an
electrodeposition of some type, but I not clear about the
details of sputtering! If anyone on the list knows how aqua-
aura is made, I'd appreciate an explanation! hale

Subject: Re: Mystic Topaz

There has been a lot of discussion about Mystic Topaz on
the Faceter's Digest. It is a radiation treatment used on
colorless topaz that goes slightly under the surface. (in
other words, you can't re-cut it, or have it recut in order
to repair a scratch). I don't know about how rare it is.
But since most FD members saw it for sale on the QVC
channel, I expect that there may be a fair amount on the
market. The consensus of the FD was that Mystic Topaz was a
way to market clear topaz that could not be color enhanced
by any other means.

Giovanna Fregni

Subject: RE: Mineral Oil as a Trim Saw Coolant

I've got a friend who's been using automotive automatic
transmission fluid (oil) in his 18" saw for years. He cuts
lots of rock, quantity, sizes & types, & has had no unhappy
experiences. Best thing about it is it's free! Check with
any of the shops in your area that repair automatic
transmissions. They usually have lots of old oil that they
have to pay to dispose of. Usually they'll give you some if
you bring a container & ask for it. Some may charge a small


Subject: BIO: Doc and Liz McKay

We subscribed to this Digest some time back, but neglected
to send information about ourselves. We started lapidary
work to create custom cabochons for our jewelry and became
fascinated by opals.

We started buying larger and larger amounts of opal, and we
have become opal dealers who sell jewelry. We have been
using Hi-Tech equipment to cab our opals for about two years
and are very pleased with it. We enjoy reading about all of
the materials discussed on this forum and do work with other
materials ourselves from time to time.

We appreciate the sharing on this forum.

Doc and Liz McKay

Gold Rush Jewelry
PO Box 635
Fairplay, CO 80440

Subject: WTB: Red Horn Coral Fossils

I'm interested in purchasing some good quality red horn
coral fossils. Please contact me if you have any to sell,
or know of a source.



Handmade Knives by D. Fronefield
"Specializing in meteorites and other exotic materials"

Subject: FS: GEM SILICA SALE (with correct URL)

We have a good sale of GEM SILICA CHRYSOCOLLA from PERU:

For US$ 250, including shipping, you will receive :
5 KILOS of Rough GEM SILICA-Including AAA Quality
( Blue, Blue green, Green, TRANSLUSCENT )

MINING CENTER PERU ( Click on Gem Silica)
Fax: 51-1- 4498492

Subject: FS: Obsidian

Hello! I have a piece of obsidian for sale; it weighs 5
pounds and all that I want for it is 20.00$. Now that is a
good price compared to what I bought it for. I got it for
60.00$. I'm moving and no longer need it nor have space for
it. It is all one piece and has never been tumbled. If you
are interested e-mail me then we can talk.


Subject: FS: 18" Slab Saw for Sale

Hi Hale it was a pleasure for both Frieda and I to be with
you and all our other old friends as well as new friends at
Wild Acres again. Sorry to hear of additional problems with

The saw I have to sell it is a Covington series 700 18" slab
saw; it is in excellent condition with the 7 speed feed and
a 9" holding vise. The blade is in almost new. I am asking
somewhere in the area of $1500-$1600 FOB St. Louis but will be
willing to listen to offers. Can be palletized and shipped
by common carrier or picked up here if the buyer wanted to
see our famous arch. I have all parts list and instructions.


Leon Kosher

Subject: FS: Belt sander


I'm selling a Belt Sander on E-Bay. The URL is:
This is just a heads up to list members. This is my first
E-bay auction. Hope I did it right.


Subject: SHOW: Knoxville, TN

The Knoxville Gem and Mineral Society invites you to attend
the 9th Annual Gem, Mineral and Jewelry Show in Knoxville,
TN on October 15-17, 1999. For more information, please
e-mail me at or call me at (423) 691-8603.
You may also access the Show information page on our
website at:

Location: Kerbela Temple, 315 Mimosa Avenue
Knoxville, Tennessee (423) 573-1901

Hours: Fri 10-6; Sat 10-6; Sun 11-5.

Admission: Adults - $3.00; 3 day pass - $5.00
Children 12 and under - Free

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