Edited and Published by Hale Sweeny
Web Site: http://www.lapidarydigest.com
Associate Editors: Geo. Butts, JR Shroeder, Steve Henegar,
Margaret Malm, and Sam Todaro
This list digest contains the following message subjects:
1. LapDigest News for Issue No 277 - Mon 5/29/2000
2. RE: Field Trip to Australian Opal Country
3. NEW: Designing a New Lapidary Workshop
4. NEW: Info on How-to-do Stone Mosaics/Pietre-Dure
5. NEW: Calculating Rim Speed of a Saw Blade
6. RE: Calculating Rim Speed of a Saw Blade
7. RE: Keeping Track of Stone Weights
8. RE: Keeping Track of Stone Weights
9. RE: Hazards: Chemical Pneumonia
10. RE: Hazards: Chemical Pneumonia
11. RE: Hazards: Chemical Pneumonia
12. RE: Problem with Polishing in Tumbling
13. WTB: Change of Color Star Sapphire
14. Bio: R.A. Griesinger
Subject: LapDigest News for Issue No 277 - Mon 5/23/2000
Well, wt least one of our members liked Margaret's letter
from Australia. He wrote: "Thanks a lot for the great stuff
about opals in Australia. I loved the reading."
Her second letter in published below.
And Ernie Ogren must have liked the work of the Web Techs;
he wrote: "Thanks for whatever the Mindspring web techs did
to clear the Digest site as I am now able to get it up, and
I did nothing on my end."
Memorial day has come and gone, and those of you who have
been on the list for some time know that I was in WWII and
on Memorial Day I focus on one of the several people I knew
who did not come home. Kind of my way of keeping them alive
and honoring them. Last year it was Hal Major. This year
it was Lt. Col. Roy Martin, Jr. Roy was a tank battalion
commander and he died at Bastogne. His body was carried out
by members of his battalion on top of a tank, in honor of
his courage and leadership. Roy was a couple of years older
than me, but I grew up and played with his younger brother
John Warren and in playing with him, got to know Roy Jr..
We will always remember you, Roy, and thank you.
Now you guys have a great week. I'm going to attend the
ceremony in which MY older brother James receives one of
Clemson University's highest awards for service to the
University. Then I'll go to William Holland School for a
week's training in glass fusing.
These trips interfere with getting the Digest published. I
have ordered a lap top and will load all Digest stuff into
the lap top and take it with me so that I can work on the
Digest on the road.
In the meantime, you guys have a bunch of fun, stay safe,
and play with those you love.
Subject: RE: Field Trip to Australian Opal Country
(Or: An American Opalholic in Paradise, Part 2)
Well! Did we make it through the flood to Yowah? You betcha!
In fact, although it was still a question of "Flood Boat"?
Or "Flood Truck'?; by the time we got there the flood had
receded very rapidly and we were able to drive across! Which
was great, as it meant we could take our luggage with us!
Our tourist luck again!
Yowah is very different from Lightning Ridge. Much smaller,
more intimate. Barbara knows everyone in town! And they were
all eager to meet us -- and help us. The town is about 6
blocks long, and 2-3 blocks wide. Their water, like
Lightning Ridges, is from an artesian well. But Yowah's
yields hot water -- about 135 degrees. This is piped
directly to the houses, and so water heaters are really not
needed. They usually have a tank that they use to hold water
for the "cold" water to cool, before using it. It is
slightly sulfur-y, but not too bad.
The mines are right across the road from the highway. Many
are open cut, in contrast to Lightning Ridge where open cuts
have recently been discouraged. But there are some
underground ones, too; we visited one this afternoon. (NOT
a tourist mine!) There are fifteen (yes, that's fifteen)
shafts leading down into it. Part of the ground has been set
aside as a "fossicking" area, where anyone can go and look
for Yowah Nuts and gorgeous opal. This is prime territory,
in contrast to most places where the fossicking area is a
barren (or something slightly salted) tourist area.
A large block of ground is tied up in native claims, which
are still under negotiation and thus not being worked just
now . Seems that when the land became available for native
claim, the natives all rushed out and filed on everything,
and there are 4-5 claims for each parcel! Barbara McCondra's
mine is called the Boomerang, due to its shape. We have been
looking assiduously for opal, and have not had too much luck
as far as finding any $10,000 opals. But we've really gotten
to see how things are done in the mines. One day her friend
and partner Trafford Hughes brought in his loader and
scooped up about 3 loads of materials from the material
Barbara is going through, and stuck them into a but
"trummel", which is a rotating perforated drum that just
tumbles them and separates them from all the surrounding
dirt, etc. We got 3-1/2 5-gallons of buckets full of
potential "nuts" back, washed them in a small
(hand-cranked) washer (like a very small cement mixer) and
then cracked them.
Oh! And while we were standing around watching the trummel
(on Trafford's claim) I looked down and found a gorgeous
opal on the ground at my feet! And he let me keep it!
And one day the local fire engine -- complete with sounding
siren, came to wet down the heaps to make it easier to spot
any opal that was exposed. But we've found a lot of
absolutely stunning cabs and rough at prices that would
probably floor you back there, as we were buying direct
from the miners. We also did some "specking" (looking over
the leftovers, as it were) at Gwen Burney's mine. She is a
good friend of Barbara's, a lovely homey lady who has
helped her with the cooking, too. She also does cutting,
and we bought some great stuff from her mine. And then
visited the open cut itself and watched her working. It
is one of the claims where power equipment is allowed, and
she uses a small jack hammer. She let me do some jack
hammering (we all got to if we wanted to) and it happened
that when I was doing it she got into a good section and
brought out 1/2 5-gallon buckets of really nice opalized
wood. She invited me to come back and bring her more good
Mining laws vary a great deal from state to state in
Australia, and also in how assiduously they are enforced.
For instance, in Lightning Ridge, which is in New South
Wales, you have to get a license for each piece of
mechanical equipment, at $1000 each. And each piece of
equipment has to pass a very stringent mechanical
inspection. Everything has to be absolutely perfect. I can
certainly understand that the brakes have to be good, and
the tires, etc. But when someone is failed for a small spot
of rust, that is really going too far. It appears, on the
other hand, that these rules and regulations are not being
enforced on the large concerns. Just for the little guy.
It has been said that they are trying to drive out the
little miners, simply because it is easier for the state
to keep the books on the taxes they collect. So they are
driving out a lot of the miners, who are going to places,
such as Queensland, where they are not so particular
about the licensing.
We also had another adventure -- not really having to do
with opals, but --- on our way over her from Lightning
Ridge we stopped for a few minutes in a small town, and the
lady barmaid brought out a baby kangaroo -- a Joey --- that
she was raising (temporarily), as its mother had just been
killed. We all took turns holding this remarkably cute
little guy and having our pictures taken with it. 'Roos are
killed by the hundreds by peoples cars; they come out about
dusk and go hopping across roads with out looking (like our
deer) and get smashed. Often it is a mother carrying a Joey
in its pouch. And often that Joey dies a miserable death;
starving or being eaten alive by the wild animals that
consume the mother 'roo. This one had been rescued by a
more thoughtful driver.
Yesterday evening Michael came back from Eulo (the nearest
small town) after an error, got out, said "we have a small
problem" and opened up the jacket he was carrying to reveal
-- another Joey, that he had rescued on his way home,
it's mother having been recently hit by somebody and killed.
What to do? Ron had some experience along this line, and we
called the barmaid in Bolen for feeding advice. In order to
keep it warm (they have a little higher body temp than we
do) it was bundled up in jackets and flannel shirts, a
couple of bottle of warm water added, and I got to cuddle
it through the evening. Joy! It is so cute!. I named it
"Outback". And it slept with Ron, who the next morning
really looked like a new father!. Apparently Outback had
tossed and turned, and he had to put on a sweatsuit, as
Outback kept nuzzling him looking for a nipple. We figure
he's about a year old. Fully covered with fur (soooo soft!)
and is bit enough to hop about a bit. And ate a little grass
from the yard today, I understand. We will take Outback with
us when we leave, as far as Bollan, and leave him with the
barmaid who has the other one. Regretfully, tomorrow morning
we must leave and start heading home. We've had a really
If you are interested in really seeing these opal fields,
and trying your hand at it, on a non-touristy adventure, go
with Barbara and Ron. They are tops!
Ta for now!
Subject: NEW: Designing a New Lapidary Workshop
I thought I might get an interesting thread going here.
We are building a house and I finally get to build my
"dream" lapidary workshop. I will have about 12'x 30 to
work with and have already planned for a separate vented
saw room. Although I have been involved with the hobby for
25 years, cabbing and carving, I'm always looking for good
Now for the question: "what are your suggestions, ideas etc.
that I should incorporate in my new shop i.e. bench heights,
lighting, exhausts etc." Thanks for your help.."
Subject: NEW: Info on How-to-do Stone Mosaics/Pietre-Dure
I'm trying to track down instructional books on stone
mosaics/ Pietre Dure. I have been teaching myself at night
through trial and error, and I need to know the "how to"
behind it all. Any information would be greatly
If any of you guys want to write up something of stone
mosaics or Pietre Dure, I'd sure like to get it. Who among
you does this kind of work? (Lemme know, please, if you are
Subject: NEW: Calculating Rim Speed of a Saw Blade
Someone on one of these lists posted the formula for
calculating rim speed on a rock saw and the ideal rim speed
for a saw blade. Can they kindly repost the information?
Tim Fisher, 1995 President, Pacific Fishery Biologists
Ore-ROCK-On Rockhounding Web Site
Subject: RE: Calculating Rim Speed of a Saw Blade
The circumference of the saw blade is Pi*d where Pi =3.1416
and d is the blade diameter.
For a 14 inch saw, the circumference would be:
14 * 3.1415926 = 43.982 inches or 3.665 feet.
Multiply that by rpm and you get feet-per-minute.
3.665 * 1725 (typical ungeared RPM of electric motors) =
6322 feet per minute
My rock saw gears down by a factor of 2 (4" pulley on saw
and 2" pulley on motor)
This would give 6322/2 = 3161.06 feet per minute or
52.684 feet per second.
I haven't bought a blade for a while, but my last couple
had a phamplet with the makers recommendation for saw speed
as feet per minute. If the 3161 is not in the recommended
range, then I would change the 4" pulley out to give a
factor that meets the recommendation. I do know there are
now some "high speed" blades that require this.
Date: Sun, 21 May 2000 18:48:47 -0400
Subject: RE: Keeping Track of Stone Weights
Most jeweler's supply carry Tanita scales. I have model
#1479, 100gm maximum, can vary .1-.2gm. The model #1475T
1200gm capacity, can vary 1gm. Both these sell $80-100. I
also have a Tanita Model #1478 carat scale, .50ct capacity,
0.001gm variance. It lists for $375.
I would like to sell the model#1478 used, if interested,
contact me off list.
Subject: RE: Keeping Track of Stone Weights
Take a small envelope (or prescription bottle) and put your
valuable cutting specimen in it. Mark the weight on the
outside and leave space to keep a running total.
When you take some out to slab/trim, weigh before and after
to determine how much was lost in the cut and subtract that
weight from your total (keep a separate total of losses).
Put any trim scraps back into the container.
Subtract out each piece as you cut it. Weigh it before and
after cutting to determine your grinding loss (keep a
separate total of losses).
Your label on the outside should always show the weight of
material remaining in the envelope/container as the bottom
line of your running tabulation that might look like...
Mineral Description, location, source, cost
Date Stock -Cutting -Grinding -Finished OnHand
(grams) (grams) (grams) (grams) (grams)
1/1/00 100 .5 1.5 6.2 91.8
1/2/00 91.8 .6 1.5 6.2 83.5
..and these are just made up numbers, but you get the idea.
When you get done you will know the original weight and
cost, how much was lost on the trim saw, how much was lost
on the grinding wheels, and how much was lost as uncuttable
scrap pieces. You can then figure true cost for the
You finally have an envelope of little scraps that you can't
cut. If they were one stone instead of scraps it would have
been usable. By recovering the true cost thru record keeping
you've reduced your cost of these chips to nothing. So glue
them to the back of business cards, write in the mineral
name (location, etc), and give them to kids or beginning
rockhounds as micromount samples. You can even have fun
telling them what it was 'worth' from the original
cost/gram (or put it on as a 'price tag'). Every pebble pup
needs a gem in their collection. Why not make it top
Please visit our family web pages at http://Tomaszewski.net
Subject: RE: Hazards: Chemical Pneumonia
I use two different oils in my saws; Almag in the smaller
saws (12" and down) and mineral oil in the big saws. I
treat the oil with a substance from Raytech called Mist
One of my customers has profound allergies; he was in my
shop last week and asked me what I was using now in my 12"
saw. I told him I was still using Almag, and he wondered
why his allergies weren't kicking in - I showed him the
Mist Killer bottle. The stuff is great, and I haven't been
able to see any difference in saw performance, although
it's been too recent a switch to tell if blade life may be
Subject: RE: Hazards: Chemical Pneumonia
The easy way to totally eliminate mist from cutting oil is
to add a container of STP or a similar oil additive to your
Ore-Rock-On and Pacific Fishery Biologists WWW Sites
See naked fish and rocks!
Subject: RE: Hazards: Chemical Pneumonia
Raytech makes a cutting oil additive called Mist Killer
that is supposed to reduce the amount of mist generated by
saw operation by 90 %. Has anyone tried it?
A web search on "oil mist reduction" turned up articles on
the successful use of mist suppressants in mineral oil-based
lubricants for high speed machining. Similar compounds are
being developed for water based lubricants.
A wide variety of filters are used as mist eliminators in
industry. A fan would be required to circulate the mist
inside the saw hood through a filter. Are there any
inventors in this group?
Ray Prater, Jr.
Subject: RE: Problem with Polishing in Tumbling
To add my bit to this subject, I had a similar problem some
time ago, but mostly when tumbling slabs. The answer that
I came up with was to add glass beads to the final polish.
These beads were originally intended to control the
thickness of the glue line when laying up composite
structures (carbon fiber). Over here it's known as
"vaquashene". The beads themselves are only 50 or 100
microns in diameter and I add about a tablespoon full. The
beads carry the polishing compound and prevent flat areas
from sticking together.
Problem is, I couldn't give you any clues as to what this
material might be called in the US or where you might find
Barry L, SRB Stones.
Subject: WTB: Change of Color Star Sapphire
I once had a color change Star Sapphire but now I don't. I
was wondering if anyone is interested in selling such a
stone?? I need a 4 to 5 carat size stone for a mans ring.
Cabbed so that star is seen on the face up and desire long
legs. It must have change of color properties: Raspberry red
to blue or Purple to blue. Willing to pay!!! Please contact
Subject: Bio: R.A. Griesinger
I'm very new to lapidary work. In fact I have yet to cut
my first piece.
I'm currently a member of "Gem and Mineral Society of
Lynchburg" (Virginia). I have enjoyed 'the hunt' for the
various minerals in our area. However, as in all things
change is just around the corner.
I am now in possession of an older lapidary unit and in
need of a source of replacement parts so I may pursue this
avenue with in the mineral world.
My unit is: Beacon Star, 6" holiday combo "D"
Any of you who have used this type unit and would like to
offer some advise please do so.
Rog (aka "G" & "Greasy")
Welcome, Rog. On our website is a page of all manufacturers
and who is supplying replacement parts. I just copied it
for you: "Contempo Lapidary Equip. Mfg. Co. was formed
through the acquisition of Highland Park, Beacon Star,
Frantom and a few smaller companies. In 1998, Contempo was
bought out by Diamond Pacific, who should be contacted about
spare parts for machines made by any of the above companies.
Good luck, and ask specific questions about your unit! hale
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