Administered by Hale Sweeny (

This list digest contains the following message subjects:

1. LapDigest News. Issue #21 Wednesday 7/9/97
2. NEW: How do I saw a base at an angle?
3. RE: Are There Hand Methods For Lapidary Work? (Hand lapping opals)
4. RE: Are There Hand Methods For Lapidary Work? (Hand lapping cabs)
5. RE: Slabbing of nodules
6. RE: Change in Opals Colors over Time


Date: Tue, 8 Jul 1997 15:31:30 -0400

Subject: LapDigest News. Issue #21 Wednesday 7/9/97

RE: Books on Tumbling, Lapidary Tips, Commercial Ad Policy, Contents Table

....I would like to assemble a list of books on tumbling to go along
with the 'book' or file on tumbling which is in the Archives. If any of
you have a book on tumbling which you really like (regardless of how
old), please send it's title, author, publisher, date of publication,
and ISBN in a note to me at the address shown below, and use the title
TUMBLE or TUMBLING on the subject line.

....And don't forget to also send any lapidary tips to the address
below. I have NOT been overwhelmed by the number of tips I have
received!!! (smile)

....In ISSUES #16 and #20, you may have noticed ADs for commercial houses
selling cabbing rough, among other things. We encourage interaction between commercial houses and the Digest, as people in commercial houses have a lot of specialized information which we can use, and we could not get by without their products.

Our policy on ADs, is set forth in AD-SOP.TXT, and may be found in the Archives. It is designed to encourage participation by dealers and commercial houses, but also to keep the Digest from becoming flooded with advertisements. I encourage anyone wishing to place commercial ads in LapDigest to get a copy of our policy.

....Finally, you will find a file in the Archives named CONTENTS.txt,
which contains the titles of the contents of each issue. I am now
working on a computer program to develop an Index from these.

Administrator, Lapidary Digest Mail List
Durham, NC

Date: Wed, 9 Jul 1997

Subject: NEW: How do I saw a base at an angle?

This query is really about how to set up a piece to be cut in the vice, or
what kind of jig or fixture can we build to hold the piece in the vice. This is a description of the first situation. Other situations will be described later.

Consider that I have a piece of stone say 4" x 4" x 6", from which I want
to carve an object to sit on the 4 x 4 base, except that I want it to lean
backwards at 15 degrees, say. What kind of jig or setup do I need to hold
it in the vice of a slabbing saw to cut the base at the desired 15 degrees? (assume here I want to carve it after the angled base is cut.)?

Any help appreciated!!!

geri arms and hale sweeny

Date: Tue, 8 Jul 1997
From: intarsia <>

Subject: RE: Are There Hand Methods For Lapidary Work? (Hand lapping opals)

Customers who buy pieces of opal rough from us at shows tell us that
they use emery boards to bring out the fire in the opal. They do this
while watching t.v. It would certainly require a lot of time and
patience, and would not work for those of us who really cut and polish
opal, but these customers are happy doing it, and enjoy the end result. It's certainly not for everyone! Less expensive than a Genie, and they
only do one piece!


Date: Wed, 9 Jul 1997

Subject: RE: Are There Hand Methods For Lapidary Work? (Hand lapping cabs)

We had a member in our club, now deceased, who hand made his cabs.
He also took his equipment to school classes and I believed he gave
some to those who wanted to try their hand at home.

I will try to describe his way. He called it 'stropping a stone'. And it
was very much like stropping a razor. His frame to hold the leather was (as
near as I remember) 3 to 4 inches in width and 6 to 8 inches long. Leather was tacked across the long way, each 'strop' for a different grit of
diamond power. He would dip stone in a little water and use the same
motion as one would to sharpen a razor. His cabs were on dop sticks.

I might add that he made some very beautiful stones this way, but didn't
make too many! ALL his stones were first class or better.

Good Luck


Date: Tue, 08 Jul 1997

Subject: RE: Slabbing of nodules

While some small pieces of rough are very difficult to hold in a
vise for even 1 cut, most can be held for that first cut. If you can hold
it for one cut, you don't really need to set it in cement, Plaster of Paris,
or anything else. Once you have a flat surface (and assuming that your saw
doesn't leave huge, rough gouges in the surface) you can glue each flat
surfaced piece to a wooden block with waterglass, sodium silicate. Just
spread a little on the wooden block, plop your rock down on it and go to
bed. Next day you can saw to your heart's content. If your wood block is
square, the last slab you cut should be just as true as the rest of them.
The last slab can be removed from the wood by soaking in water for
several days. I day to dry, 1 week to unglue is just about right for
I bought my waterglass at the Wal-Mart pharmacy for $2.58 a pint. A
pint should last me several years.
Incidentally, waterglass is strong enough to hold very substantial
sized rough that is difficult to put in a vise, as well as the small stuff.

Herb Luckert

221 Marquette Ave
South Bend, IN 46617

Date: Wed, 09 Jul 1997

Subject: RE: Change in Opals Colors over Time

You may find that the opal was treated with a sugar solution and burnt.

By setting the opal in water and letting it sit, it has lost the carbon
blackness of the sugar treatment over time. This would also account for
the loss of sparkle.

The brown patches are an indication that the opal was not totally
impregnated with treatment and the surface was only just treated.

Sometimes this opal depends upon a certain water content being present
to maintain color. So a suggestion would be to place the opal in water
for several days and see if the color improves. If it does then use
opticon to treat the opal and this should ensure the color will hold a
lot longer for you.

Cranestone Gems.

Tanzanian Gemstone Rough Direct Mine Prices
Australian Opals Rough & Cut At Wholsale Prices.
Australian Rough & Cut Sapphires
Web Site:
To subscribe to the Digest, send a message to,
with the word SUBSCRIBE DIGEST as the subject of the message. Other
commands you may use are: UNSUBSCRIBE DIGEST to quit, HELP to receive
a page of help instructions on the use of the list. Old issues of Digests
are archived and the list of the old issues and other files in the Archives may be obtained by using DIR on the subject line. Then <GET filename> may be used on the subject line (without brackets, of course) to obtain a copy of the file. Type filename exactly as it appears in the directory, including the extension. Do not cut-and-paste filenames into the subject line.