Edited and Published by Hale Sweeny
Web Site:
Associate Editors: Geo. Butts, JR Shroeder, Steve Henegar
and Margaret Malm

This list digest contains the following message subjects:

1. LapDigest News for Issue No 242 - Wed 11/3/1999
2. Review: Oct 1999 issue of Lapidary Journal(LJ)
3. NEW: Australian Jelly Opal versus Crystal Opal
4. NEW: Search for Custom Technology's Web Address
5. RE: What Adhesive to Attach Rock to Wood
6. RE: What Adhesive to Attach Rock to Wood
7. RE: What Adhesive to Attach Rock to Wood
8. RE: What Adhesive to Attach Rock to Wood
9. RE: How deep should a saw blade run in coolant?
10. RE: How deep should a saw blade run in coolant?
11. RE: Cutting Dop Sticks
12. RE: Flashes of Light when Cutting with SiC
13. RE: Need new part for Hillquist saw.
14. RE: List of Chatoyant Rock
15. RE: List of Chatoyant Rock
16. RE: Filling Cracks in Opals
17. RE: Filling Cracks in Opals
18. WTB: Sandstone for Carving Bas Relief


Subject: LapDigest News for Issue No 242 - Wed 11/3/1999

Well, I did go to William Holland School - about a 7 hour
drive - and spent Monday in a class with Joe DePetro. Great
class. Got a phone call Monday night -- Anne had fallen
and had broken the ball in her right hip. So I came back on
Tuesday in time to see her go into the operating room to
get an artificial half-hip. Then she was in recovery till
Saturday. On Sunday, we moved her to a rehab nursing home
where they will try to teach her to walk again -- this
time with a walker!

I'm kinda down in the dumps! (Wish it was the dumps of the
Princess mine!!)

Thanks for your suggestions about how to make the Digest
shorter. Over the next few weeks, you will see some of
those ideas put in place.

James Dumas' column on Lightning Ridge will return next

Have fun. people!! And stay well!!


Subject: Review: Oct 1999 issue of Lapidary Journal(LJ)

This is a review of the articles in LJ of possible interest
to lapidarys:

Special Tools, Special Care. Page 26.

Kristina Logan has a short article on how as jewelers and
gem cutters we use a wide variety of special tools to make
our crafts. Her main point is that we take great care of
these tools, but the one tool we all use may not get that
same care. Our hands! They are the most important tool in
our shop!

Making the Cut in Idar. Page 58

Si & Ann Frazier have a nice story about Germany’s
cutting capitol. The picture on page 58 and 59 is worth
the price of the issue all by it self. Grinding wheels as
tall as a man, how cool.

An Agate & Amethyst Vacation, Page 77

Tim Twomey talks about taking a summer vacation in Thunder
Bay’s amethyst country. What I found most interesting was
that Lake Superior agate and Thunder Bay agate are not at
all alike.

Agate "Pottery" Pin, Page 128

Wanda Little & Colleen Reigh have a Beginner stone and
Cutting project. It calls for 3 ¼" banded agate or jasper
slabs with horizontal patterns.

South Dakota’s Fairburn Agates, Page 177

South Dakota’s Fairburn Agates, by Roger Clark is reviewed.
I only mention this as a shameless plug, since to me Roger
Clark is a hometown boy who made good and is good friends
with some of the members of my local club. Our club has a
copy donated by Roger that I have looked at and it is a
great book for any collection. FYI: Roger didn’t pay me for
this and I don’t make anything if you buy the book.

JR & Janet Schroeder
J & J Jewelry

Subject: NEW: Australian Jelly Opal versus Crystal Opal

Hi all,

Could someone tell me the difference between Australian
jelly opal and Australian crystal opal?



Subject: NEW: Search for Custom Technology's Web Address

Hi to everyone,

I tried to contact Custom Technology using the information
in the May 99 LJ Buyers guide which gave an email address
and a website address. The website gave me a 404 error -
no such site listed - and the email was bounced back to me
on a similar basis.

Can anyone tell me how to contact them if they are still in
business. I really would like their email address and their
correct website address if they have one rather than a
postal address.

Best regards to all and a cheery wave to any UK readers.

Roger Young
King's Lynn, England, 120 miles due north of London.

Subject: RE: What Adhesive to Attach Rock to Wood

<<Any ideas on using an alternative adhesive for attaching
a rock to a block of wood so you may hold it in a saw vise
for cutting?>>

I've been using silicone caulk for several years. Haven't
had a rock come loose yet & I cut some big ones, over 30#.
I run the saw room at our lapidary club, we've got 5 saws
from a 10 - 24". Any rock that needs to be dopped for
sawing gets the silicone caulk treatment. We use everything
from 1x2 to 4x4 for dop sticks. The caulk needs to be 100%
silicone caulk, it doesn't matter what the color is.

Our method of dopping is to place the stone to be dopped in
a tray of oil sorb so the area the dop will be attached to
is up & the dop can be attached so it is plumb. This method
allows the stone to be held in any position. If the stone is
real uneven (slanted) I cut the dop stick to an angle that
approximates the slant of the stone. Pump a coating of caulk
on the dop with a caulking gun & apply the dop to the stone.

Adjust the stone as necessary in the oil sorb (sand or kitty
litter) so the dop is plumb & let it set for about 24 hours
to cure. If the stone is real slanted, the dop may have to
be held in place to prevent it from slipping out of position
until the caulk is cured.

Don't put too thick a seam of caulk between the stone & the
dop. It's a waste of caulk & allows for flexing between the
stone & the dop. If the dop is removed from the stone later,
a saw (cross cut or hack) works well. If you don't want to
buy a big tube of caulk, small metal tubes you squeeze by
hand are available.

It works for me!


Subject: RE: What Adhesive to Attach Rock to Wood

Sodium silicates bond will loosen with time. I was shocked
when the instructor in the S.F. club took my rock and hit
it against a table to make sure it was still adhering
properly to the wood after it had been sitting for one week.
Well, it was a tough agate and took the punishment all right.
It is a good idea to pull on the rock before putting it into
the saw to make sure you have a good bond. If it comes
loose during sawing you could ruin a saw blade.

Rose Alene McArthur

Subject: RE: What Adhesive to Attach Rock to Wood


One thing I noticed about these comments is that most do not
say if the rock is rough or flat. If you have a rough piece
of material such as Mozarkite or Brazilian agate try this
mixture. Mix crushed agricultural limestone (not Lime as
used in whitewash) with liquid sodium silicate to form a
very thick paste. Pile this mix on a piece of 4x4 about 3"
long, then set a clean rough piece of material on it. Add
more of the mix if desired to fill any spaces that are left.
allow to set a day or two until hard. Then saw in an oil

If you have a water based coolant, cover the cement with a
coat of auto grease. When thru slicing your rock (you can
slice thru the cement with no problem) soak the butt end in
warm water with a bit of soap in it to brake down the cement
and separate the last slice of material.

This mix was sold thru the Lapidary Journal many years ago
and I figured out the ingredients and made my own. It takes
a little time but is very cheap compared to epoxies,etc.

Subject: RE: What Adhesive to Attach Rock to Wood

Lou mentions using Elmer's or carpenter's glue. I agree
with the Elmers, but *don't* use carpenter's glue! It is
waterproof and you will have a fine time trying to get the
rock and wood apart after the last cut!. I know from
experience! I was advised to use carpenter's glue, did, and
after soaking in water (including hot) for over two months
they show no signs of relaxing their loving embrace of each
other! I am apparently faced now with the old hand saw and
then chisel routine.

So, beware!


Subject: RE: How deep should a saw blade run in coolant?

<<I have come into the possession of an older 18 inch saw
and was wondering how deep I need to run the blade into the
coolant. I am now running the blade about 1/8 inch into
an unknown oil that came with the saw.>>

Run it deep enough to carry a reasonable amount of coolant
all the way around the blade and into the material you're

<<Also, the lead screw that drives the vice has about 1/4
inch play. Should I tighten it up?>>

Where is the play? In the lead screw bearings on the table,
or between the lead screw and the vise? What direction is
the play? If it's parallel to the screw, it probably won't
hurt. However, if you have the means to tighten it up, you
probably should, short of creating too much friction.


Subject: RE: How deep should a saw blade run in coolant?

I always ran the blade on large saws about an inch deep in
oil. I also put bricks in the sump along the opposite side
from the saw. If you add bricks or other materials you have
to clean the saw more often. I always use Almag or an oil
that is right for use in saws. Other oils may not hold up
with a reduced amount in the sump.

Steve Ramsdell

Subject: RE: Cutting Dop Sticks

My simple method is to place a length of dowel on a flat
surface (I can seldom find one in my workshop), take a VERY
sharp knife and place the edge on the dowel at the point
where it is to be cut. Put plenty of downward pressure on
the knife blade and roll the dowel back and forth under the
knife. If it is a thin dowel, you can cut it right through
in a few rolls. If it is thicker than about 1.5 cms you can
easily snap it after a few rolls. The whole business takes
only a few seconds. In my case the fact that it might not
be 'square' doesn't matter; I use enough warm dop wax to set
the stone exactly as I want it.

For a pear shaped stone or similar, grind the dowel end to
fit roughly to that shape, but slightly smaller.

For making the first cut in a heavy rock (about fist size)
I cut a piece of thick wood to an 'L' shape which will fit
in my saw vice, and use plenty of dop wax (I often re-use
some of it) with the lower part of the rock resting on the
lower part of the 'L' which takes some of the pressure off
the dop wax.


/\ John Burgess
/ /
/ /
/ /__|\

Subject: RE: Flashes of Light when Cutting with SiC

On Thu, 21 Oct 1999 12:06:27, wrote:

<<The light flashing phenomenon can be observed if you just
take it (the apache tear) into a dark room and strike it
like a flint. It will emit very small sparks of light. It
seems to be a characteristic of the volcanic stones,
probably has to do with the same things that make a flint
strike fire.>>

Yes, in this case, it's exactly like flint. You're
producing white-hot particles, which not only emit light,
but can be used to start a fire. Any silica will do this.


Subject: RE: Need new part for Hillquist saw.

Yes, Hillquist Inc. is still in business in Fall City,
Washington. Their catalog shows all of their saws and a
coolant tank. Call or write to Kevin Tame the President,
for a catalog and for parts for your saw, just tell him
what size blade and he will tell you if they are still

The catalog I ordered from shows an aluminum 3
compartment settling tank, but they now make them out of
plastic. It comes as a two piece plastic tub in a tub,
filter, pump and installation kit. I drilled a hole in the
bottom of the tank for a sink type drain and hose that
comes with it, and mounted the coolant nozzels (copper
tubing) next to the blade and now, no more cleaning out
the sump, only the small plastic tub.

Their address is: Hillquist Inc.
35502 S. E. Fall City Snoqualmie Rd.
Fall City, Washington 98024
Phone (206) 222-6968
Ernie Ogren

Subject: RE: List of Chatoyant Rock


Add sillmanite to your list. It has a fibrous structure
and if the fibers are aligned, a nice chatoyancy.

Sorry I can't cite a reference offhand. Personal

Rose Alene McArthur

Subject: RE: List of Chatoyant Rock

There are multiple sites for these two in Northern Minnesota
Cuyuna Iron Range that are still open. Many were quarries
now turned into some of the 11,300 lakes Minnesota boasts
but some like Rabbit Lake and Portsmouth still have dump
piles. There was a water treatment facility built about 10
years ago that uncovered a fair amount of blue silkstone.
This has been covered over now though.

Binghamite is either red or gold (or both) and very
chatoyant when oriented correctly. Silkstone, same material
except a lower percentage quartz, has been found in red,
gold, purple, green, blue, etc. I have one favorite piece
with 5 colors.

Binghamite was first identified by William Bingham in 1947
if I remember correctly. I sat on his lap at a rock show
in 1957 - I was 2 at the time. Thanks to pictures I know
it happened, I don't remember it.

Both are US varieties of Tigereye. The May 1989 issue of
LJ has an article by John Kammerer on the material. I own
some of the specimens in the article or at least the next
slab over from the same rock and hunted a few times with
John. The pictures don't do the material justice. He and
several others used to go up to the Cuyuna range almost
every weekend in the 50's and 60's hauling material home
literally by the truck load.

Hope this gives a better view of a US chatoyant material.



Subject: RE: Filling Cracks in Opals

Awhile ago I cut a nice big round cab out of a piece of
flawless rose quartz and during the cerium oxide polishing
let it get too hot and got a fracture. I'd heard you could
oil a stone and the crack would disappear so I put the cab
in a paper cup of mineral oil and vacuumed it for awhile,
no luck. Is it possible to make the crack disappear? How?

Also, I bought some Opticon awhile back and never used it
and wonder if that would work? Even after reading the
instructions for the Opticon it doesn't really say WHEN to
use it and what kind of results you would get.

Any pointers here?

Thanks all....


Subject: RE: Filling Cracks in Opals

Solution: Slow drying epoxy, a vacuum pump, a glass bowl and
a rubber pad. Fasten hose from pump thru rubber pad on a
flat surface. Place opal on waxed paper on rubber pad. Next
cover opal with epoxy, place bowl on rubber over opal and
turn on pump. The vacuum removes the moisture from the opal,
and epoxy replaces the moisture.

A refrigeration type vacuum pump is best.

Hobo: I would be afraid that the vacuum will pull some
mixed but still fluid epoxy into the pump and out the
exhaust line, and that the epoxy will polymerize among the
vital parts of the pump over time and will ruin the pump.
Would appreciate any comments on this concern. Will it
happen? hale

Subject: WTB: Sandstone for Carving Bas Relief

Does anyone a have a source for sandstone? My stone
sculpture instructor has lost her sight due to macular
degeneration. She can see about 12"-15" and can still
carve in bas relief. She could use carving quality stone
about 1"-2" thick and 8"x12" or we can get chunks cut

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