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This list digest contains the following message subjects:

1. LapDigest News for Issue No. 95 - Mon 12/22/97
2. NEW: Replacing Lortone Lap Polishing Pad
3. NEW: Fire Obsidian
4. RE: Fire Obsidian
5. RE: Working Honduran Black Opal
6. RE: Refurbishing Old Equipment
7. BIO: Barry Longbottom
8. BIO: Don and Francis Mason


Subject: LapDigest News for Issue No. 95 - Mon 12/22/97

Almost Christmas!! Where has this year gone? 1997 has been a
great year for me in one regard: The Lapidary Digest has been
my bright spot since we started on June 6. The Digest has
come a long way. With this one, we have published 95 issues;
we have a full and active Archives (about 15-25 hits per day)
and will soon have a duplicate set of Archives on a web page.
The membership has grown to over 720 and grows each day! As
far as I can tell, this is the only publication in the US
solely devoted to lapidary arts.

I initially envisioned the Digest as a cross between a usual
mail list and a magazine, where much of the content would be
query-response material, and the other material would special
'commissioned' pieces, and this has pretty much been the way
it has happened. I want to keep this format, and will try to
get special pieces written for the Digest to satisfy your
interests. The ones in the works now include:

.. working with ammonites
.. how to do channel work (mineral inlay)
.. electroplating and other methods of surface decoration

If you have special interests you want covered, please write
and tell me about them.

So as we come to the end of the year, I want to wish each of
you a very joyous Christmas time and a prosperous, peaceful,
healthy and happy 1998. I thank each and every one of you for
your support and involvement in the Digest and look forward
to an even better New Year!!

Have fun, and be sure to hug the ones you love.


Subject: NEW: Replacing Lortone Lap Polishing Pad

I bought my Lortone flat lap used with no instructions. The
polishing pan had a cloth-like material glued to the metal
pan--something like a dense terry cloth. This material is
now almost worn away and it looks like I will be down to bare
smooth metal soon, just like my grinding pan. (My grinding
pan has no grooves in it, as I have heard that many do have.)
Around the perimeter, where the material was protected by
being under a plastic bumper, the same material is still in
place, almost 1/8" thick.

Question--What do I do now, coach?

Herb Luckert

Subject: NEW: Fire Obsidian

I enjoyed the advice on rainbow obsidian. Please tell me if
there are any different procedures to follow when working
with fire obsidian. I bought a piece on a silent auction
this summer and could use some advice.

The piece that I have is about the size of two small T-bone
steaks with another half of one piled on the top. The bottom
half of the black stone has flow lines of mahogany up to 1/4".
You might think: "Ah, this stone may have some gold sheen in
it". In the upper half, the flow lines only show up as thread
width on the weathered outside. Where someone chipped out a
big conchoidal chip, we hold a flashlight up to fracture and
see pale greyish lavender banding reflected. As we continue
to rotate the stone, at about l5 degrees to the flow lines,
you suddenly get a flash of red-orange, and then there, lines
of brilliant red, orange, and a little green suddenly flash
up, as brilliant as a fire opal with a black background. They
are almost fibrous in texture instead of the patchy areas of
color in opals. Perhaps, you think, it is a rainbow flash
from a deeper conchoidal fracture. But at that angle you can
see reflections dully under the weathered surface all along
the flow lines at the same angle. I have seen one cab of this
at a rock show several years ago and it was very striking. I
suppose you would take all of the precautions that a person
would take in working obsidian. I just wondered if there
would be any other suggestions anyone could give.

Thank you,
Rose McArthur
Non commercial republish permission granted

Subject: RE: Fire Obsidian

<<Having never seen fire obsidian, I wrote Roger Pabian and
asked him to comment on how to work it. Here is his answer.
Thank you, Roger. I owe you one! -hale>>

I haven't cut any fire obsidian for quite a few years, but
there are a couple of things that would be helpful to know.
Are we dealing with slabs or with un-slabbed pieces of rough?
If the material is already slabbed, then the process is
pretty much that of marking the cabochon and shaping and
polishing it. If it is a piece that is not slabbed, then it
is a question of properly orienting the stone before slabbing
it. The fire obsidian that I cut has an appearance that
mimics opal---there are numerous flecks that show a play of
colors. The rough needs to be oriented such that the slabs
large surfaces lay nearly parallel to the layers in the
obsidian. Even with proper orientation, there is no guarantee
that the piece will produce fire.

Keep in mind that obisdian is very brittle and heat
sensitive. If you are working with carbide, keep the wheels
well dressed and sand wet. I polished it with tin oxide and
leather, but Sinkankas recommends cerium and felt. I have not
ever done obsidian with diamond so I can't make any
recommendations here.

Roger Pabian

Subject: RE: Working Honduran Black Opal

I have dealt with a firm out of Tucson Az for a number of
years now for stable turquise and honduran opal. The opal is
so stable I am able to further darken the material by giving
it the same color treat I use on andamooka matrix opal. This
consists of the stone being in heavy, hot sugar water for
days and then into a bath of 97%, hot, sulphuric acid for a
few days more! The honduran material is softer than precious
opal but no sign of the crumbling one expects of the natural
stone. I don't know if they deal with "special" orders, as
they are my source for the final treated material (both
honduran, and turquise). Give them a call and see what you
can work out. I suggest asking for Ron at:

1436 E. Benson Hwy.
Tucson, Az. 85714

robert larry crum

non-commercial republish permission granted
(Ed.Note: Details of the 'sugar' treatment and discussions of
the treqtment are included in the file "Treating Opal.txt" in
the Archives. hale)

Subject: RE: Refurbishing Old Equipment

At 08:15 AM 12/14/97 EST, you wrote:
<<As far as paint goes, any good oil based paints will work
fine (try RustOlium in Machinery Gray). Poly paints and
epoxies are better but more expensive. Lacquer is OK (dries
really fast) but stains from some coolants.>>

I'd go with Hammerite, not much more $$ than RustOleum but
sure lasts longer and is much tougher. Rough up the surface
with a piece of 60 grit silicon carbide sandpaper first and
it won't peel off.

Tim Fisher, 1995 President, Pacific Fishery Biologists
WWW -- See naked fish and
Date: Sun, 21 Dec 97 13:51:42 UT
To: "Lapidary Digest" <>
Subject: BIO Barry Longbottom

We live near Cambridge, UK, and I've had an interest in
lapidary for 20 years or more, inherited from my Mother who
used to collect and tumble pretty pebbles from the beaches of
the Isle of Wight.

My own interest has always been directed towards
experimentation with different materials in terms of how best
to work with them. Favourite materials are banded agates.

Some years ago I set up a small business buying and selling
rough rock, mainly because it was the only way to obtain
decent material, and I'm still a member (though rarely
active) of the British Lapidary and Mineral Dealers
Association (BLMDA).

My current employment doesn't leave me with time to do much
these days, my equipment and rock lies untended in my
workshop, a garden shed which is not a very inviting place
during the British winter. But I retain my interest and
fascination with the hobby and do hope to get back to it

Barry Longbottom

Subject: BIO: Don and Francis Mason

My wife (Frances) and I are professional wirewrappers having
studied at the W. Holland School in Young Harris, Ga, a place
we recommend without reservation. We have taken
silversmithing, cabbing, beading and opals. We cut mainly
opal and fiber optic. We have won awards at the Australian
Nation Gem Show. As far as we know, and its a small island,
we are the only lapidaries in Bermuda.

Don Mason
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