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This list digest contains the following message subjects:

1. LapDigest News for Issue No. 148 - Wed 6/24/98
2. NEW: How to Use Sonic Tumblers
3. NEW: Vibrator Tumbler for Opals
4. NEW: Lapidary Shop Tip - Replacing V-belt
5. NEW: Book on Banded Agates
6. NEW: GFI Protection
7. NEW: How Do You Identify Stones?
8. NEW: Crystal windows
9. NEW: Homemade Lapidary Grinders
10. RE: Home Made Saw Filter Systems
11. RE: Workshop Setup Advice Needed
12. RE: Can Layered Common Opal be Used for Cameos?
13. RE: Source for Sphere Stands
14. RE: Source for Sphere Stands
15. WTS: Montana Agate Slabs
16. WTB: 12" or Larger Saw


Subject: LapDigest News for Issue No. 148 - Wed 6/24/98

Still trying to play 'catch-up' with all the notices which
you sent in - so if you haven't seen yours, just wait -- it
WILL appear soon!

Issue 150 will be devoted to a description of how to make
channel work jewelry. If you have any patterns you would be
willing to share, please send then to me at or at 3500 Cambridge Drive, Durham, NC
27707. I am trying to find a website for them.

Be safe .. Have fun...


Subject: NEW: How to Use Sonic Tumblers

Several members in our club have gotten used Sonic Tumblers.
So they call on me, now they want to know how to use them. I
don't know the makes they have, but I guess they all work
about the same. Please help with:

What kind of grit?
Do you run it dry or wet ? If wet, water? and how much?
Are the steps the same as with barrel tumblers?
What type of polish?
Do you polish wet or dry?

All my tumbling has been with the barrel type.

Thanks in advance
Nisqually Valley Rockhound Society
Yelm, WA.

Subject: NEW: Vibrator Tumbler for Opals


I'm an opal cutter in Australia. Most of my stones are cut
by hand but I have a number of free forms that I would like
to tumble in a vibrator.

Does anyone know who supplies the vibrator tumblers that will
fit multiple bowls at the right price.... and can you give
me some advice on the right grits to use. I've been told
that 220, 400, 600 and tin oxide will do the trick.

I have experimented before using these but found the final
polish was difficult to get. It was still quite mat, and
not shiny enough.

Please let me know how much the right machine would be. The
bowl would be around 6" diam.



Peter Brusaschi

Subject: NEW: Lapidary Shop Tip - Replacing V-belt

I have just solved a problem that crops up periodically and
may do the same for some of the other lapidaries on the list.
I occasionally have a v-belt break that drives the screw feed
mechanism on my slab saw. This is a problem because there is
no way to put a a circular belt back on this unit without
completely dismantling the saw. I tried several different
things when this has happened in the past, with no luck.
Always had to take half a day right when I least could spare
it and dismantle the saw.

Today while debating what to do with the saw down again I
happened to notice my daughters nylon rope for pulling her
snow sled. It was approximately the same thickness as the
broken drive belt. I wacked off a piece long enough to fit,
retied the sled up short, and took it to the shop. I threaded
the rope thru the pulley path, and using a candle, melted the
two ends. I then stuck the two ends together and as soon as I
could [that sucker was hot!] molded the repaired end with my
fingertips. I held it till it was cool, finished threading
it on the machine, and what do you know! It works great!
All for about 25 cents worth of rope and a candle!

Should work for other situations too! The only problem I see
is next winter I will have the sled wacking my heels when I
pull the kids around! Hope this helps others as much as it
helped me.

Ron Schanfish

Subject: NEW: Book on Banded Agates

I came across a fascinating educational circular at our NWFMS
show in Billings, Montana this week-end. This may be old hat,
but it was new to me. It is called "Banded Agates, Origins
and Inclusions", and is published by the Conservation and
Survey Division, University of Nebraska-Lincoln, Lincoln, NE
68588-0517. Price lists are sent on request. It is Education
Circular number 12. I paid ten dollars for it from a dealer
in Patagonian agate. It was signed by one of the authors, and
I suspect probably was a little more expensive than from the

Anyway, the reason that I was impressed with it, is because
it gives origins for all the features we lapidarists observe
in the agates we cut. Every statement is well documented.
There is an impressive bibliography that can be used for more
in-depth research, and a glossary for anyone who is not up to
date on all the geologic terms. There are beautiful color
illustrations of agates with the features that they are

The new information for me was in the explanation that they
gave for the source of the silica that is deposited. The
origin of the silica in all agates come, they say, from
volcanic ash layers, or from silica freed in the
recrystalization progress that glassy volcanic material
gradually goes through. There has never really never been a
satisfactory explanation as to how agates end up occurring in
sedimentary deposits. However, they offer a very reasonable
source for the silica available to form agates there--the
voluminous amounts of volcanic ash that rain down into the
sea when there is a volcanic eruption.

This especially was impressive to me because we went on a
field trip yesterday (in conjunction with the show) to a
place in the Pryor Mountains. We were looking for black
agate nodules with thin lacey white lines in them. Our
collecting site was an impressive cliff composed of layers of
limestone. There was a plethora of flint in many colors,
also translucent reddish brown jasper with fossils of coral
and crynoid inside. The silicified material was in very
identifiable layers, and it was easy to imagine that these
reflected times of volcanic activity in the ancient ocean.

This circular would be a good addition for any club or
individual rockhound's library.
Sincerely, Rose McArthur

"non commercial reprint permission granted"
Rose: That circular was written by one of our list members,
Roger Pabian. He has submitted quite a few good additions to
this list. He has also written "Minerals and Gemstones of
Nebraska", available from the same address as Educational
Circular #2. Roger sent me copies several months ago for
review; they will be reviewed sometimes soon. Glad you liked
the Agate book; I think it is SUPER! I didn't remember the
costs, but I thought they were each less than $10 from the
University. hale

Subject: NEW: GFI Protection

Subject...GFI Protection

Bad luck may run in streaks
Gold also runs in streaks [veins] too.
My Digest is back !!!!!!!!!!
Enough of this rejoicing.

There has been much discussion about drilling, cutting,
cabbing and the like. All using water H20 + 120 volts. For
your safety and to eliminate electrical shock hazard, it is
mandatory that you have your lapidary equipment protected
with GFI protection. I can not emphasize this strongly enough,
whether it is a Drermel drilling and cutting gems, a saw, a
cab machine or any thing else.

The human heart beat is controlled by the bodies' micro
currents. Your doctor uses an EKG to read these currents.
It only takes 5 milliamps to stop this heart. Most of your
lapidary equipment is connected to circuits protected
by 15 or 20 amp fuses or brakers. This is 4,000 times
the current need to stop your heart. And many of our older
hearts are somewhat weaker than they were in our youth.

An old wise man once said, " Have fun, but.. Be safe...."
We can not do the latter if your lapidary equipment [and you]
are not protected by a Ground Fault Circuit Interrupter...GFI.

COST is minimal. A good GFI receptacle cost less than $10.00.
INSTALLATION is simple if you can......
1..Cut off the power
2..Use a screwdriver
3..Follow the inclosed instructions
ALTERNATIVE. .A GFI UNIT built into a three foot cord is
available at any electrical parts counter.

You wear seat belts in your car.
You have smoke detectors in your home
You carry all kinds of other insurance
At least consider the DANGER of lapidary equipment
[with water every where] not protected by a GFI device


DURHAM N.C. 27707-2027

Thanks, Mick, for very timely and valuable advice. Alright,
he has told you -- now everyone... INSTALL GFI RECEPTICLES!!
Stay safe -- and -- Have fun!!! hale

Subject: NEW: How Do You Identify Stones?


Hi again!

I've been wanting to ask a question about identifying stones.
I bought a parcel of cabs from an estate, and am having some
trouble identifying some of them. The malachite and
carnilian and such are easy enough... but there is nephrite
jade and green adventurine and some of it isn't marked. They
look a lot alike to me.

Also there is alot of Burmese Jade, which must come in lots
of colors. The problem here, is the unmarked cabs. Some may
be the jade, but some look like they may be others. In
particular, there is a semi translucent cab that is a blueish
green. Very pretty. The texture is different than the
marked jade. Anybody have any ideas on how I can identify


Sandra Good <>

Copying and reprints are okay.
Check out what I have up for auction# LIFE IS GOOD!

Subject: Crystal windows

Hi all
Have been a LapDigest subscriber for a long time and always
enjoyed the reading but never had much to say. Anyway...I
purchased a couple of crystal windows at my last gem show and
am curious to know if it is a "for real" item.

They consist of a variety of egg shaped crystals with white
*frosting* coated on the outside. Then a small slice is taken
off to make the window. The little tags say Made in Brazil.
They are unique and fun to look through at light or fire but
when adding these to my collection I'd like to know if nature
made them this way, or if they got a little help from man.
Just being a simple collector I'm not familiar with the cans,
can'ts and dohows.



Subject: NEW: Homemade Lapidary Grinders

(Craig mentioned, in an earlier post, that he had built his
own lapidary grinders. I asked him to tell us how he did it,
and here is his answer.)

Hale, the story on these grinders isn't that good but here

About 8 of 9 years ago my old 4 wheel unit had finally reached
the point where it was shot. The wheels still turned and the
water still flowed but the pan was shot. It was one of the old
sheetmetal type from 1975, the kind with a grinding stone,
expandable drum and flat end plate. Also the kind that would
rust, and rust it did. At the end there was more water on the
floor and my bench than ever hit the stones. Not having the
bucks for a new unit was really starting to be a pain. I'd
been scraping my pennies togther to buy my first set of
diamond wheels, had finally gotten enough and now had nothing
to run them on. I had considered having a new pan built, but
why should I when the bearings were also about shot?

Looking through the paper one night my wife-to-be spotted a
small 4 line ad for a garage sale: Used Lapadary Equipment.
Address, Phone Number, etc. Great I thought, maybe there's a
unit here for cheap. It could happen you know. Upon ariving I
found that what they were talking about was two 18" stand up
type steel flat laps, slow rotating, transmition driven
wonders. When I ask the price, the guy told me $125.00 each.
Well, there went the grinder unit money. Or at least most of
it. Just then he says "If you would you be interested in these
too, I'll make you a good deal." He shows me three duel
shafted, heavy duty 8" arbor units, the free standing type.
A Highland Park, a B.W Morant and a Poly. All in good shape,
none with shields and $75.00 for all three.

How could I miss? I got them all home and started thinking:
"If these things had pans, shields and water fittings, they
would be just what I need". Using what I had kicking around,
I constructed the pans and splash guards from a couple of old
2 x 4's and a sheet of plywood and then covered the whole
thing with fiberglass resin. The pans turned out to be 22"
wide by 17" deep and 4 1/4" high. Totally waterproof and
guaranteed not to rust. The backsplash, sides and top were
nothing more than plywood, coated the same way with resin and
holes drilled in the top for small T-Valves. Water is
supplied via plastic tubing hooked to a $ 7.00 swamp cooler
pump sitting in a plastic tub and is drained into a bucket.
The motors came from a second hand store, used about $20.00
each and aren't 1/4 H.P.

Ugly as this setup is, it sure can cut a stone. Even though I
could get somthing better (at least newer), I can't for the
life of me see why I'd want to.

Most of this is sort of irrelevant to what you wanted but I
thought you might like to read it.

Craig Nielson
Thanks, Craig. It was interesting. For the list, he explained
what a swamp cooler pump was in Issue 147, under the Subject:
<<RE: Home Made Saw Filter Systems>>. hale

Subject: RE: Home Made Saw Filter Systems

Plastic (is there any other material nowadays?) swamp cooler
pumps don't like some coolants and will deteriorate therein.
One coolant that comes immediately to mind is (since I use
it) is ALMAG OIL put out by Texaco. The first part to fail
will be the impeller blade attached to the bottom of the
driving shaft.

Alternatevely, I would suggest using a metal submersible-type

Paul H. Miller

Subject: RE: Workshop Setup Advice Needed

I forgot to say that I have an area of about 20 feet by 20
feet (6m by 6m for the Europeans) available on the ground
floor - thanks Trudy. The rest will be retail space.

Andy Parker

-- non-commercial republish permission granted --

Subject: RE: Can Layered Common Opal be Used for Cameos?

Should be no problem. I have samples of precious opal as
cameos and it looks wonderful. Opal is not such a hard stone
to carve. In fact one of the easiest if you're careful. Not
sure what colour potch you are talking about but you would
need to think about a base for the stone. Either obsidian or
the like. Only problem with most American opal is that it is
prone to cracking. It also happens with some Australian
fields too.

Hope this helps.

Peter Brusaschi

Subject: RE: Source for Sphere Stands

Depending upon the extremes one is willing to go to, here is
an idea for sphere holders - broken coral. At the western
most point on Ohahu, Hawaii is Kaena Point. You have to hike
in to Kaena Point, 2 to 3 miles depending upon where you park
and whether you come from the south or the north side. On
the sourthern beaches at Kaena Point there are thousands of
broken pieces of coral. They are about 0.5 to 1.5 inches in
thickness (diameter of the coral), two to three inches in
length and width, and have multiple branches of the coral.
Some of them can be used for displaying rough material and
fossils, and I have no doubt they would work for spheres too.

I am sure there are other places that similar coral can be
found. I recall someone telling me about a similar beach on
Maui, and I'd guess that similar coral could be found in
non-commercial republish permission granted

Subject: RE: Source for Sphere Stands

Various plastic sphere stands are available from Sylmar
Display Stands, P.O. Box 362, Youngstown AZ 85363-0362,
phone (602) 933-7301. They have a catalog. Their prices
seem to be fair, although not as low as some sellers at

I prefer wooden drapery rings, available at most drape shops
and department stores. I like them especially for larger
spheres; they don't distract from the sphere as happens with
the more ornate metal or plastic stands. For display in a
case at shows, I like a plywood sheet with rings cut from
plastic irrigation pipe glued thereto, then covered with a
loose soft tan cloth. Again, nothing distracts from the
spheres--they seem to float on the cloth.

John R. Duncan
Non-commercial prepublication rights granted.

Subject: WTS: Montana Agate Slabs

Bill Carrothers here; I'm the guy with the vibrasonic drill.
We e-mailed back and forth a few times.

I wanted to tell everyone about a part of a web page my son
has up on the net. He is a jazz pianist of some note, (but
seriously), and sells CD's from his page. He also set up a
section for me that one could find direct, that shows some
Montana hearts and crosses and slabs (not yet), that are for
sale. The slabs are wonderful quality Montana, as I have a
connection on 90 sections of previously unhunted ranch
country that is loaded with the best agate I've seen in 30
years of hunting the area.

If I sell the jewlry, fine, but the slabs give other people
a chance to work with some good stuff if they like Montana
Moss (dendrite) agate. I probably have 500-1000 slabs and am
cutting all the time.

Anyway, here's the page and tell me your thoughts:


We will add much to this soon.

Bill Carrothers

Subject: WTB: 12" or Larger Saw

I`m looking for a saw or saws 12" or larger for cutting rough.
Please e-mail at Thanks in advance

Mark Condron.
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