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This list digest contains the following message subjects:

1. LapDigest News for Issue No. 111 - Wed 2/4/98
2. NEW: Crystals in Black Jade
3. NEW: What is a Laser Gem?
4. NEW: An Open Opal Mine in Spencer, Idaho
5. RE: Info on VibraTek Rock Polisher
6. RE: Info on Turbo-Carver
7. RE: Info on Turbo-Carver
8. FS: Cabbing and Faceting Rough


Subject: LapDigest News for Issue No. 111 - Wed 2/4/98

We are preparing a list of all the books on Lapidary we can
find and will print this list sometimes soon. Then we want to
start publishing reviews of books both old and new. If you
want to help by reviewing a book or two, please drop me a
note and I will add your name to the list. The books you may
review are ones which you probably already own.

The first book reviewed will be GEM CUTTING SHOP HELPS, which
was published by LapJour some thirty years ago. That review,
prepared by Andy Parker, should serve as a model for other
reviews. I thank Andy for suggesting this whole project in
the first place.

The list of books is being put together by Lloyd Duncan. I
know what a big effort this is, and I thank you, Lloyd, for
doing this.

Please remember to put the words: -Non-commercial republish
permission granted - at the bottom of postings so clubs can
copy your post in their club bulletins.

Have a great week, and remember to hug those you love, and
tell them so.


Subject: NEW: Crystals in Black Jade

Recently I won a couple of slices of jade in a contest at a
rock show. It is black, and if you look closely you can see
a pattern of delicate black crystals across it. I am told
they are an iron mineral, maybe magnetite. Is there, perhaps,
a procedure to trace the crystal design with a deposit of

Thank you,

R. McArthur

Subject: NEW: What is a Laser Gem?


I was given some faceting rough called "laser gem". It is a
light blue under fluorescent light and a light purple/lilac in
natural light. Can anyone help me with the chemical
composition, or any other information on this synthetic gem

Thank you, Norm

Subject: NEW: An Open Opal Mine in Spencer, Idaho

Hale and List:

In my article some time back on making opal doublets/triplets,
I reported (from a source) that public fee digging had been
suspended at all of the Spencer, Idaho opal mines. But I see
that the March issue of Rock & Gem carries an ad announcing
public digging dates for 1998 at "The Original" Spencer Opal

According to the ad, those wishing more information should
send a SASE to P.O. Box 521, Salome, AZ 85348 (October to
April) or HC 62 Box 2060, Dubois, ID 83423 (May to
September). Phone numbers are (520) 859-3752 and (
208) 374-5476, respectively.

Rick Martin

Free to publish elsewhere

Subject: RE: Info on VibraTek Rock Polisher


My Mother is the rock tumbler in the family and she has
owned a VibraTek tumbler for nearly two years. The idea of
using an electromagnetic coil for the vibration is a good
one. However, the units design and construction, other than
the coil itself, was not so well done.

The first machine we had, broke the second day we ran it.
The problem was that the post that is used to adjust for
optimum vibration, wasn't attached very well. I removed this
item after attempting a repair and jury rigged a different
way for adjusting. That worked fine for about 9 months when
the second problem happened. The electromagnetic coil just
stopped working. We called the manufacturer and they had us
ship it back to them for repair. I don't know what they did
with that machine. About a week and a half later they sent
us a brand new machine, with new tumbling barrels and
inserts, and, no explanation as to what went wrong with the
old one. The new machine had the same problem with the
adjusting post and I had to replace it as I had done with the
old machine.

Whenever you change the weight you have to change the
adjustment for optimum vibration. It takes quite a bit of
attention when tumbling as there is no way to seal the tubs
against evaporation. The reason the tubs have an evaporation
problem is that they were made of a too thin plastic to stand
up to the vibration and they start to crack after about 2 to 3
months of tumbling.

My mother gets a very good rough grind, but hasn't been
able to get a real high gloss polish. I think that this is
in part due to the machines weaknesses. Another factor is
that my mom may not be as patient as some of the
tumbler/polishers in our club.

If I were going to buy another medium to large capacity
tumbler I would not buy another VibraTek, but rather one of
the eccentric cam vibrating tumblers or a rolling barrel

Tom Burchard

Subject: RE: Info on Turbo-Carver

I would suggest checking into the Turbo-Carver particularly
inquiring if there are any assurances about the life of the
handpiece and its bearings.

I have not tried these high speed hand pieces for lapidary
but did some investigating a few years ago when I was
considering trying them for metal smithing projects. What I
learned was that the bearings in the handpieces are
effectively the "weak link" in this system. A decent
handpiece with substantial bearings is fairly expensive.

My dentist is also a close personal friend who gave me the
names of his sources for dental equipment. One was willing
to sell reconditioned units including the handpiece and
driver for something less than $1,000. When I saw a unit
advertised in the lapidary literature I called and discussed
the fact that it was priced well below what I had been quoted
by the dental supply house.

I was told candidly that the unit for lapidary was NOT
expected to last and was a "sample" or "hobby" unit. When it
wore out it was not rebuildable. The idea was that a lapidary
could try the high speed unit for a while and, if it was to
their liking, then buy the better, more expen$ive (and
rebuildable) unit later.

Russ Madsen

non-commercial republish permission granted

Subject: RE: Info on Turbo-Carver

I use an SCM Turbo @ 400,000 RPM for several applications.
Mine is not the late model but it is fine. I bought the
compressor too, so it sets up independently. I use both
carbide and diamond bits as appropriate. The survey made by
WOOD Magazine (Feb'98 issue) is pretty accurate and

Hope that helps! Cheers!

Ira Abernethy, Jr.

Subject: FS: Cabbing and Faceting Rough

Well cutters, January is over and thus the garnet sale.
February is here with a new sale!

For cabbing kind of folks, how about some GREAT lapis for 20
cents a gram? Regular price was $0.35 per gram. I have pieces
ranging from 10 grams to 725 grams.

For facetors here's one hard to pass up: 10 grams each of
garnet, amethyst, citrine, peridot and tourmaline. Regular
10g sample packs retail for $140 total. Until Feb. 28, all
50 grams for $100. (there are only 20 of these specials!)

One more special: I received a consignment of tumbled
peridot. 80% facet grade, the other 20 would be perfect for
gem trees. $0.55 per gram in lots over 100 grams. Under 100
grams, $0.75 per gram. NICE material.

Have a beautiful day.

Mark Case
Randleman, NC
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