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1. LapDigest News for Issue No. 137 - Monday 4/27/98
2. NEW: Tumbling Question
3. NEW: A Possible Cheap and Safe Cutting Oil
4. NEW: Inclined (non-Horizontal tumblers)
5. NEW: Using Diamond Abrasives in Tumbling
6. RE: Hydrophane Opal
7. RE: Hydrophane Opal
8. RE: Opal Price Guide
9. RE: Opal Price Guide
10. BIO: Julie Hruby


Subject: LapDigest News for Issue No. 137 - Monday 4/27/98

First, I want to apologize to Tim Fisher, who put the ad in
the last two issues about the (classic) lapidary material
sale. Some time ago, I wrote some software to automatically
shorten lines to fit within our limits, and in using this
software on his submission, it shortened a line so that his
URL was messed up! ...and did this twice!! So here is Tim's
correct URL:


I looked at what he had to sell and was impressed. Even if
you are not interested in buying, do take a look at the
pictures of his Northwest cutting material.

Just got a note from Charles Ramer up at Franklin, NC (where
they have the big eastern gem and mineral shows) that they
will open their G&M Society Museum on May 1. The first show
at Franklin will be May 8-10 and the next show will be July
23-26. If you go to either of these, be sure to visit the
museum. It's free. And it is in the 'Old Jail', right in the
heart of town. Just ask; everyone knows where that is! For
more info, write Charles or Amy Ramer at <>.

My d-in-law asked if we (Anne and I) wanted a free time-share
apartment on Hilton Head Isle next week, and of course we
said yes. So I will be away for a couple of days next week.
Ah, sun... sand... surf!!!

I have added a file to the Archives on how to access the
Archives. The name of the file is AccessingArchives.txt, and
you may GET it in the usual way!

Please don't forget to add the four words: 'Non-commercial
Copy Permission Granted' to the end of all your submissions,
and this will allow clubs to reprint queries and answers in
their bulletins.

Have fun!


Subject: NEW: Tumbling Question

Am I vastly mistaken or did I read somewhere in the past that
certain stones could be tumbled in corn meal with no water?

I normally use grit and tin oxide.

Floyd Dopler

Subject: NEW: A Possible Cheap and Safe Cutting Oil

After having read all the comments about using bad oil, and
having used the expensive stuff from MLS and also
experimented with Propylene Glycol, I decided there must be a
better way. I searched and questioned people that I know have
used cutting and cooling solutions for various industrial
processes such as machining of metals and other hard and
brittle materials, I think I found one that meets all
criteria for efficiency, safety from toxicity, environmentally
safe and inexpensive. The stuff costs about 20-25 cents a
gallon, doesn't wear out and when it gets weak just add more
of the base solution to what's left after cleaning the sludge
out of the saw sump. My only thought is that I only have a 6"
saw and haven't tried it on a larger slabbing saw yet.

This test will take place in about 3-4 weeks. The material is
a highly soluble, stable protein in solution manufactured by
a leading chemical producer .. I have no financial or other
interest in this stuff except if it works it will make
slabbing easier and less costly to do. As more information
comes to me, I'll get it on line . If any interest in this
just E Mail me with name and address so they will be able to
send out more info on it. P.S. In the metal industry it is
disposed of by sewer after straining to remove the metal


Subject: NEW: Inclined (non-Horizontal tumblers)

I have been away for some time so I haven't had much time to
go through my mail so forgive me if there have been recent
discussions on this.

Are there any companies that make rotating (drum) tumblers
that do not have to be covered? Specifically the type that
would be inclined vertically so the tops could be left open
without any cause for spilling the contents. I am not
mechanically inclined but would like to know if anyone knows
of any designs or manufacturers of such tumblers.


Dan Otchere
Unionville Ontario

Subject: NEW: Using Diamond Abrasives in Tumbling

Can diamond impregnations as in the discs ever be used in the
tumbling process by incorporating them in the drums? Anyone
with answers please?


Dan Otchere
Unionville Ontario

Subject: RE: Hydrophane Opal

<<What (can) I do to maintain the color of the stone as it
appears when it is fully saturated with water?>

Take a picture! :> As far as I am aware, there isn't any way
to change this or it would be a standard treatment!
Hydrophane can be gloriously colored ... until it dries ...
then it goes opaque and frequently loses play of color and
turns white. Take a piece of the rough that's dried a bit and
touch it to your tongue... you can feel it actually sticking
as it sucks the moisture. I started cutting one piece that
was a lovely apricot shade with play of color and very
transparent ... there was hydrophane under the transparent
layer and a few days later, the stone went opaque with white
lines. Also crazed terribly. I recut and it seems to be
stabilized, no more crazing, and has developed a slight play
of color --- but it's still opaque.

It can take over a year to dry completely! The one I cut had
been out of water 8 months.

<<Can I simply allow the stone to dry out then apply Opticon
to it?>>

I'd be curious if you do this to see what happens.

<<Would I do this before cabbing the stone or after it is

It would have to be after cutting, because the Opticon will
not permeate all the way through the stone. I think this is
the inherent flaw... the untreated material may still try to
draw in moisture, or draw it from the Option solution and
cause crazing. Think it makes more sense to keep it as a
novelty, or a viewing piece in a specimen dome.

PS I'm still around even though I have a backlog of LD's to
read yet! Rockhound nose must have sniffed out the opal posts
| Carol J. Bova |
| Home of The Eclectic Lapidary e-zine |
| |
non-commercial republish permission granted

Subject: RE: Hydrophane Opal

You should dye it, actually it is a burning process with
acid. But I have an idea that might brighten it up. Make a
doublet or triplet. Take a thin slice and back it with black
agate/onyx (by the way, the process to make Black Onyx is the
same as coloring this opal) and use a clear Quartz top. The
thinness of the Opal,and the magnification of the Quartz top
should bring out some decent color. Opticon is just a
fracture filler or sealer.

Mark Liccini

Subject: RE: Opal Price Guide

<<I'm planning on getting into selling the opals I cut and am
in the process of learning to price them properly. I have
Paul Downing's "Opal Identification and value". His method is
based on an updated reference called The Guide put out by
Gemworld International....>>

Actually, it's the other way around. The Guide uses his
system (he is one of their contributors).

<<Does anyone know if there is a site on the net that
publishes basic opal prices?>>

Unfortunately, don't think there is such an animal. Opal
pricing is highly subjective and based on the attachment
the owner to the material, general availability, and the
market's whim. The rarity of color, number of colors,
pattern, and intensity of brightness will in fact determine
how highly prized a given stone is.

The very best way to learn about pricing is to go to The Opal
Show presented by The American Opal Society the first weekend
in November in Anaheim and look, and look and look. Just about
all of the dealers (except equipment supply people) deal
primarily in opal of every variety, and from every location
imaginable. It is an opalholic's dream!

One of our members was showing the Downing 'brightness kit'
at the workshop a few weeks ago. It does give you some idea
of relative brightness, but there is so much variation in
depth of color, pattern of color, number of colors, that no
one set of 5 stones is going to give you an easy way to say,
ah, this is a $10 stone and this a $1000.

You can see a $50,000 stone though, and know in your gut why
it's worth that ... the intensity is enough to bring tears to
your eyes and it glows with an inner fire that is visible
across the room! (Had that pleasure once upon a time!)

Perhaps the best suggestion for net looking is to simply
browse as many opal sites as you can. There are many excellent
ones. I particularly like Tim and Barbara Thomas's House of
Tibara site for clear, easy to understand information.
Especially look at the section on "How to Buy Opal" at:

I'd strongly recommend joining the American Opal Society if
you're not already a member! The monthly newsletter is one of
the best opal education tools available.

And Barbara McCondra does a monthly column for The Eclectic
Lapidary on Australian opal... some of which might be of
particular interest to you. (This month's is on "Opalphobia"
and Overcoming Fear of Cutting Opal). The March, 1997 issue
was on red on black opal, and why it can go for
$20,000/carat! So drop in and browse through the archives.

See you all again sooner next time,

| Carol J. Bova |
| The Eclectic Lapidary e-zine |
| |
"non-commercial republish permission granted"

Subject: RE: Opal Price Guide

In a message dated 98-04-24 10:29:41 EDT, you write:

<< I'm planning on getting into selling the opals I cut and
am in the process of learning to price them properly. I have
Paul Downing's "Opal Identification and value"...(snip)...
Does anyone know if there is a site on the net that publishes
basic opal prices?>>

I have been in the Opal business for a few years now and can
tell you that the Guide (Downing) prices are way off. Stones
that would wholesale for $1000.00 per carat if the Downing
grading system is used and applied to the guide pricing
matrix, will actually sell for closer to $100.00 per carat.
Your best bet to establish prices is to do a lot of visiting
at shows. Wear some Opal jewelry of varying quality stones
to use as comparison stones. The light is always different at
the shows and your memory will not be able to differ between
a $100.00 a carat stone and a $50.00 a carat stone a week
later so a comparison to a known set is the only way I know
to fix the lighting and memory problem.

By the way, Opal prices are some what soft now that
the Asian economy is in the tank, so you are going to be
having a "LOT" of competition from the Aussie's. I know that
I am.

Good luck though and you will find that there is a market for
top, well cut stones.

Don at Campbell Gemstones

Subject: BIO: Julie Hruby

I am a graduate student in the Department of Classics at the
University of Cincinnati, specializing in Aegean Prehistory.
My MA thesis, which I am presently scrambling to write,
covers Minoan seal production. I am attempting to recreate
and use a few of the ancient tools: bow drills, stationary
(bow driven) lapidary lathe, etc.

Most of the materials are serpentines, quartzes, and assorted
types of cryptocrystalline silica, but there are also
hematite or meteorite seals, obsidian, etc.

I am interested in any basic lapidary bibliography; would
some kind soul please email me with suggestions?

Many thanks,

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