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This list digest contains the following message subjects:

1. LapDigest News for Issue No. 167 - Sunday 9/20/98
2. NEW: Need Plans for 30"-36" Slab Saw
3. RE: Greening Turquoise
4. RE: Need Advice on Slab Sawing and Slab Saw Blades
5. RE: Ever Hear of White Turquoise?
6. RE: Ever Hear of White Turquoise?
7. RE: Ever Hear of White Turquoise?
8. RE: Ever Hear of White Turquoise?
9. RE: Ever Hear of White Turquoise?
10. RE: Cutting Jelly Opals
11. RE: Cutting Jelly Opals
12. RE: Cutting Sodalite
13. RE: Getting Started: How to Learn Lapidary
14. RE: Getting Started: How to Learn Lapidary
15. RE: Want Advice of Cabbing Set-up
16. RE: Back Issues of Lapidary Journal
17. RE: Back Issues of Lapidary Journal
18. RE: Back Issues of Lapidary Journal
19. RE: Need Advice on Slab Sawing and Slab Saw Blades
20. SHOW: Huntsville (AL) Gem & Mineral Society Show
21. SHOW: Gaston County (NC) Gem & Mineral Club Show
22. FS: Seam Opal and Opalized Clam Shells


Subject: LapDigest News for Issue No. 167 - Sunday 9/20/98

Anything sent to be published in the Digest should be sent
to <>.

Major items we are working on include: Cutting Honduras Opals,
Cleaning and Working Shells, and Scrimshaw. If you can make
any contribution to any of these topics, please write them up
and send them in.

The Digest is almost back up and running. Must recover a few
more items for the Archives, but in anticipation of them being
ready, we will publish a detailed set of instructions for
accessing the Archives in the next issue.

The next issue will be about a week away; I am going off to
Wildacres for a solid week of doing some channel work and

Take care of yourselves and have fun for a week!


Subject: NEW: Need Plans for 30"-36" Slab Saw

I'm looking for plans to make a 30-36" slab saw. If anybody
knows where I can get them or anybody that has them please
contact me at

Mike Becker
ABC6 Television

"non-commercial republish permission granted"

Subject: RE: Greening Turquoise

<<I am looking for some dark green turquoise for a repair
job I am doing. If anyone can help me, ...>>

You can oxidize any piece of Turquoise and make it the shade
of green you want. Now it's been a long while since I did it,
but I think it is just like silver, you dunk it in a "pickle"

Mark Liccini

<<Hale: I had never heard of this before, but I know Mark and
know that he has had a great deal of experience working with
stones (he knows more about changing the colors of gemstones
than anyone else I know) so I wrote him and asked: "But about
this ... do you mean you use a sulfuric acid pickle? What
concentration? So please tell me what you remember or where
I can find references!" He replied:>>

Hey I did it 28 long years ago. But I am positive about it.

Turquoise is a copper mineral and you can oxidize it. Just
like silver turns black. It turns green when the surface is
oxidized. Ask this question in the Rockhounds at Infodyn:
"How do you oxidize copper?" I don't want to give you a bad
formula. But I am correct, I'd wager on it. And you can
control the amount of green.

Did you ever see a Turquoise in an old ring, they will be
green, but you sand away the surface, sometimes need to go
deep, and it is blue again. What has happened is it has
oxidized just in the air. Now I have forgotten what chemical
you use, but for sure you can oxidize the surface of

Nice to see your list back.

Mark Liccini
Gemstone Rough Dealers Since 1970
Phone/Fax 201-333-6332

Subject: RE: Need Advice on Slab Sawing and Slab Saw Blades

I have used water only for 6 inch and smaller diamond saw
blades and usually use a stainless blade like the Ugly
Duckling. When using water with small trim saw blades I
usually wipe them off and drain the saw after each use.

I use a Beacon Star 6 inch trim saw and had the drain plug at
the rear of the saw replaced with a threaded fittings and a
piece of plastic tubing about a 14 - 18 inches long fitted
over the fitting and I put a piece of wooden dowel rod in the
end of the tube. When I am through sawing, I raise the saw up
several inches and the fluid inside the saw drains out the
tube into a pail or bottle, and I then replugged the tube.

I always use Almag oil in my 12 and 16 inch slab saws because
it disperses the heat better, materials cut better and it
keeps your saw parts from rusting. I always put my oil in
paper sacks and I get back most of my oil back cleaned.

Subject: RE: Ever Hear of White Turquoise?


In the 70s I had about a pound and a half of white turquoise
which was part of about a 10 lb.. lot. I questioned it at first
but two things convinced me. I had dealt often with the seller
and the turquoise was part of a blue/green lot, and some of
the stones were multi colored blue and white. This was 20+
years ago and I don't know where Ken is now but I'll go and
dig in the back of the safe - I think I saved one or two cabs.
The turquoise was exceptionally hard and If I hadn't seen the
mix I would have thought I had hard Variscite.

(Later Ken wrote, after checking his cab stash:)

I have two white freeform cabs 20 and 22 carats with extremely
light plasteel backing. I have two others where the matrix
lines have a little blue fringe beside them on a white stone
and three others from the same lot (easily noted) that are
mostly very very light blue fading to white.

Ash Carter

Subject: RE: Ever Hear of White Turquoise?

Sounds like Howlite (calcite). I have a 5 lb.. piece they can
have for $499! (hint: that's about 20 times it's "actual"

Tim Fisher

Subject: RE: Ever Hear of White Turquoise?

I have some white turquoise. It is somewhat rare in that it
is unusual. Is it valuable? I never thought so..........

Now and then in mining (or buying rough) you will find some
turq that has a white core. Natural assumption is that it is
turq. But it is really a hydrated aluminum phosphate WITHOUT
the necessary trace of copper which would make it turquoise.

Notice that we are not talking about 'chalk' turq which is
highly porous and nearly devoid of color; that Turq is
commonly used to make the treated material which
represents most of the turq on the market today (85-90

This really puts it in its own subcategory of the hydrated
phosphate family of where we find varascite, faustite,
chalcosiderite, etc. There is really not much of it found nor
around to make it popular, and besides, it is rather boring.
I have kept a cab of it for years for the novelty value only.
$500.00!? I'LL SELL IT! Come get it.


P.S. Nice to see you back and running again Hale. Nothing like
a little challenge to keep the edge fresh, eh?

"non commercial republishing granted"

Subject: RE: Ever Hear of White Turquoise?

I have seen some of the so called white turquoise. It is
called Dry Creek Turquoise and is very hard and nearly white
to a very light blue. I have been searching for some of the
rough but to date have been unable to locate any. I have been
told that the material is from Nevada. The coloration could
result from aluminum substituting for a portion of the copper
to lighten the color.

Bob Johannes
The Amethyst Rose

non-commercial republish permission granted.

Subject: RE: Ever Hear of White Turquoise?

I've heard of white turquoise. they sell it in Virginia City,
Nevada. I was quite skeptical too and questioned the store
owners closely. When I first saw it I figured it was probably
Howlite, but on closer inspection changed my mind. the story
is it comes from one particular mine that mines other colors
of turquoise as well and they came across this white seam. It
does look like turquoise and it has supposedly been tested
and is basically the same. I'm sorry I don't have more
specifics about chemical composition and mine names etc. but
I have seen it.

Consider yourself to have my ongoing permission to reprint as
per your policy change. Sounds like a fine idea to me. I've
probably forgotten too.


Subject: RE: Cutting Jelly Opals

<<I recently acquired several Mexican jelly opal cabs... They
are very beautiful. I looked up what we had in the Archives
about cutting and polishing these opals, and saw that we had
a file (Cutting Jelly Opals.txt), but the information in that
file was not anywhere near complete. So I will ask again: Can
anyone on the list give advice on orienting, cutting, polishing
Mexican jelly opals? Know anything about where they come from
in Mexico and how they are mined? Would you please write up
what you know and send it in? hale>>

For information on locations & mining techniques for Mexican
opal check out the October 1998 issue of Rock & Gem. There is
an excellent article by Bob Jones on Queretaro opal, which is
the main region for Mexican opal. The opal locals were known
by the Aztecs, who called it "quetza-litzle-pyolliti".

According to Frank Leechman in "The Opal Book", Mexican opal
first came to Europe in the first quarter of the sixteenth
century. The opal mines at Queretaro were discovered by a
peon working on the plantations of Hacienda Esperanza in 1855
but mining did not begin in earnest until Don Jose Maria
Siurob opened the "Iris" mine in 1870. Queretaro is located
about 160 miles by road northwest of Mexico City. The mines
are open quarries. The opal occurs in rhyolitic rock, filling
cavities in the rock, usually completely filled cavities
although occasionally opal will be found floating loose in
some cavities. It is mined by being blasted from the hillside
with explosives. The resulting boulders are then broken up by
hand to free the opal. Other lesser localities mentioned in
the references I have are at San Juan Del Rio & Tequesquipan
both of which are approximately sixty miles east of Queretaro,
Zimapan and Vila Seca, northeast of Mexico City in the state
of Hildalgo.

As far as polishing Mexican Jelly opal goes, I am not a
professional cutter, but I have been cutting opals for about
30 years & have found a method that works well for me. If you
are going to be successful with cutting Mexican Opal you need
to be aware of a couple of characteristics common with the

First, Mexican opal is very heat sensitive; it often has a
higher water content than its Australian cousin, and it can
be somewhat brittle. Before cutting a Mexican jelly I usually
leave it out of water for a couple of weeks to make sure it is
stable enough to cut. Once I am convinced a piece is cuttable,
I try to do as much of the preforming as I can without doping
the stone When I’m ready to dop, I paint the side to be dopped
with clear nail polish & allow that to dry. Than slowly warm
the stone in the oven to about 100 degrees F. (no more than
that) when the stone is warm take a dop with hot wax & press
it to the stone. The nail polish will provide a strong bond
with the dop wax; I have yet to lose a stone off of the dop
using this method.

For shaping the stone I work with silicon carbide belts on
an expandable drum. I don’t like grinding wheels because of
the shock to the stone & I don’t use diamond belts because
they cut to fast. I do any preforming on a broken-in 100 grit
belt, shaping on a 220, 400, 600 then on to a well worn resin
belt with 50,000k diamond spray for final polish. Everything
is worked very wet until the final polish. Use light pressure
through all stages.

For polishing I use a medium pressure & keep the stone moving
to avoid getting it hot. If the resin belt starts to grab to
much add a drop or two of baby oil or other light mineral oil.
If you see any kind of scratches under 10x magnification, the
belt is either contaminated or not broken in well enough.
Before polishing soft opal with a resin belt I usually polish
a couple of agate cabs to break it in.

Heat is probably your biggest enemy when working with Mexican
Jelly opal, KEEP IT COOL! One other item to note, occasionally
you’ll run across a piece of jelly which seems to have kind of
a diffuse play of colors. Hold it up to the light (so the opal
is between your eye & the light) you may have a piece of
"Contra Luz" opal. It will come alive with color when viewed
through transmitted light, similar to "Iris" agate only much
more intense. Contra Luz should be faceted rather than cabbed,
and it will make a truly amazing gem.

Every cutter has his or her own methods, the above methods
have worked well for me.

Hope this helps,

Subject: RE: Cutting Jelly Opals

MEXICAN OPAL come from two predominant places in Mexico:
Magdalena, in the state of Jalisco and the area around
Queretaro, in the state of Queretaro. They are mined by
whatever means available, by hand or bulldozer. Mostly open
pit mines in rhyolite flows.

Many have a problem with crazing and dehydration, so let it
dry for a few weeks so as not to waste your time on a "bad"
one. Some people put them under a hot light bulb for a few
hours to be certain that they are durable and worthy of

They come in many colors: colorless, yellow, orange, red,
pink, lilac, purple, peach etc. From clear to milky, like
Australian. Sometimes even blacks. Most do not have the
diffractive phenomena, but some do. These are much more
expensive and desirable. This day and age the non-diffractive
variety also sells well under the term "fire opal" or "cherry
opal". These types can be very transparent and are faceted.
The ones with diffraction are generally cabbed and can go for
up to $1000 USD per carat even in Mexico.

Mexicans dop them using an alcohol lamp and dopwax, preform
them on silicon carbide wheels with water, and finish them
dry on discs of spinning silicon carbide sand paper of
varying grits, polishing them with leather and cerium oxide
slurry. Experience is needed with their methods !

The main market for the finest ones is in Japan, not the USA.
Hope this helps,


Subject: RE: Cutting Sodalite

I have cut and polished some Sodalite, a few previously
tumbled pieces and some I slabbed from rough, with very nice
results. I really like the color and blue white mix. I found
it very easy to work with using standard methods but one piece
I polished with some brownish cerium oxide stained a bit so
next time I would probably use a different polish.

If you have a supply of rough I'd love to trade small
quantities with you. I have lots of self collected material
from California, Nevada, and Utah.

Has there ever been a discussion of trading materials on this
digest. It seems to me that shipping could be awfully
expensive on large quantities.

Have others experience with this they would share?

Hale feel free to edit this as you see fit.

Non commercial reprint ok as per normal I agree with the
writer last issue though. I would also object to commercial
use w/out permission. Even a web site. I think it is
important to protect the value of this list.

Subject: RE: Getting Started: How to Learn Lapidary

<<Also, do you have any suggestions for me that would help me
pursue my "new hobby?">>

I'm pretty new to this hobby too. If you want to get your
feet wet fast you have got to join a club. Find one or more
in your area that have shops and classes set up. Start with
a lapidary class and go on from there. These clubs are
volunteer organizations and may be less than perfect about
making you feel welcome and comfortable, but believe me, they
want new members and are anxious to help you learn about the

Volunteer to help out and you'll quickly become accepted.
Most clubs have informative programs at meetings too. If you
want to learn fast there is no better way than to join up and
start asking questions. Also subscribe immediately to some
of the magazines covering the hobby. Talk to the people in the
club and they'll recommend their favorites. I really like
Rock and Gem.

Good luck

Subject: RE: Getting Started: How to Learn Lapidary

Steve Shawn--

Let's see, if I was just starting out...

Well, I started out by getting used equipment and then learning
what features I preferred and then eventually found new or newer
equipment that fit the bill. Look at your budget and decide
what you can afford new and what can be bought used.

For starters, you would need a cabbing unit. My personal
favorites are the ones that have flat laps and run like a
turntable. The unit I have now is by High Tech Diamond Products
(often advertised as 'the All You Need machine') I think a new
setup can still be had for under $200.00. I got a deal on mine,
since I bought a demo model at a gem show. That was over three
years ago and I'm still using the original laps that came with
the machine. On the plus side: it is quiet and clean, very
little splashing. On the minus side, I didn't like the drip
tank, so I replaced it with my favorite standby, the hanging
IV bag. (for some reason this hobby inspires tinkering,
probably one of the aspects that attracts me...)

You'll also need a diamond saw. If you only use small
stones and small (under 6") slices of rock you can get away
with just a 4" saw. However, if you like to collect your own
or don't always want to buy precut slices, you'll probably
want an 8" saw, too.

There are lot of great books on rocks and gems out there.
My favorite field guides are Simon & Schuster's Field Guide to
Rock and Minerals and S&S's Field Guide to Gemstones. Don't
overlook the value of old rock magazines. My collection of
old Lapidary Journals and Rock&Gems have answered almost every
question I've ever come up with. There are a lot of them out
there and people are often willing to just give them away.

Hope this answers some of your questions. Happy Cutting.

Giovanna Fregni

Subject: RE: Want Advice of Cabbing Set-up

Goodness! You need information on cabbing? I feel like I
should be asking you questions. I was at an auction last year
where I saw faceting machines set up as cabbers. While some
people were mortified, I figured why not? If you're doing a
lot of production work, you could attach a Cab Mate unit on
the machine. Or you could just dop it up like the stone was
going to be faceted. The same grits and polishes apply
whether you're cabbing or faceting.

As I said somewhere else in this issue of the digest, I
do like the High Tech Diamond Products laps. They're long
lasting and put up with all the abuse I've been giving them.
In fact, when I realized that I didn't have a faceting lap
with my machine that was coarser that 3K, I took the 180
grit lap off of my cabbing unit and used it to preform for
faceting. It worked fine until I could get a proper 8" one
for the faceter. For polishing, cerium oxide on felt with
very little water has given me the best polish.



Subject: RE: Back Issues of Lapidary Journal

Members of the Houston Gem and Mineral Society, who are
'cleaning house' of old magazines to make room for more
equipment and rocks, take them to the club house and donate
them to our librarian's fund raising cause for additional
books etc. and sells them to newer members for a quarter. It
is cheaper than copying a large article from the library's

If you are near a rock club I'm sure the club or at least
some of the newer members can make some kind of use out of
the donation.

Good Luck
Jill Rowlands


Subject: RE: Back Issues of Lapidary Journal

If you have a rock club near you they might be glad to get
them. We sometimes put them out on our silent auction table
at our show and charge 25 to 50 cents for them . This way
the club makes a little, someone gets some good from them and
the land fill doesn't get full.

non-commercial republish permission granted

Subject: RE: Back Issues of Lapidary Journal

I still have about 3 boxes of old Lapidary Journals in my
entryway. Strange how something that useful can be so
unsaleable. I plan to haul them to the local gem club meetings
where they will probably disappear in the first half hour.


Subject: RE: Need Advice on Slab Sawing and Slab Saw Blades

Thanks guys, I think I'll be using oil. I did get some 5 gal
cans with the saw; I was just used to using water on my trim
saw though. Looks like plenty of diamond in the notches and
the blades are pretty flat. I have an old grinding wheel to
sharpen it with, so I'll give it another go!

Steven Case

Subject: SHOW: Huntsville (AL) Gem & Mineral Society Show

You are invited to attend the 30th annual Huntsville Gem &
Mineral Show, hosted by the Huntsville Gem & Mineral Society.

October 9-10, from 9AM to 7PM
October 11, from Noon to 5PM

Von Braun Center, Exhibit Hall
700 Monroe Street, Huntsville Alabama

Our theme this year is Crystals. We will have many
interesting displays of crystals and a black light room with
minerals which fluoresce. There will also be a Gem Dig and a
Mining Flume for the kids!

Door prizes and a silent auction each day. Exhibits,
Demonstrations, Sales.. Come and see us!!

Contact: Dianna Burch

Subject: SHOW: Gaston County (NC) Gem & Mineral Club Show

You are invited to attend the 20th annual Gem & Mineral Show
of the Gaston County Gem & Mineral Club.

Oct. 9 through 11, in Gastonia, NC; On the Nature Trail,
Schiele Museum, 1500 E. Garrison Blvd.

Hours 9th & 10th 9 AM - 6 PM; 11th, 9 AM-5 PM. Free admission
and parking.

Our dealers will have Rough and cut gems, mineral specimens,
fossils, supplies and more. This is one of the best little
outdoor shows in the east.

Contact: Earl English

Subject: FS: Seam Opal and Opalized Clam Shells


Could you post the following items for sale or trade.

1 lot approximately 13 oz of very nice mintabi seam opal.
Lots of red, purple green, blue, yellow fire. There is one bag
of small pieces about 20, a bag of 5 pieces, and 1 bag of about
12 pieces. This is very nice material. I am asking $2000 for
the lot or will price by the individual piece at 100 to $350
an ounce depending on the quality of the piece.

Also, 4 lots of Clam Shells. 1 lot of smaller pieces, $400,
1 lot of better pieces $500, another lot with 3 nicer mostly
whole clams $600 and 1 superb specimen that is whole extremely
nice fire in this piece $800 or the entire lot for $2000.
This whole lot has extremely nice fire throughout the pieces.
These were all hand selected for me by one of the miners that
I deal with.

Also coming soon the ultimate Opal video, made at the mines
showing most major sites. Should retail for about $30. This is
an extremely well produced video. I have seen bits and pieces
of this. I will have copies available in about 1 month.

Thanks Hale,

Tim Vogle
P.O. Box 421
Redan, GA. 30074
770-593-3962; 404-738-3548 beeper

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