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 241 -Thurs 10/21/1999
2. New: How deep should a saw blade run in coolant?
3. NEW: Need Part for Hillquist Saw
4. NEW: Instructions for Overhead Arm Polishing Unit
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: List of Chatoyant Rocks
10. RE: List of Chatoyant Rocks
11. RE: List of Chatoyant Rocks
12. RE: List of Chatoyant Rocks
13. RE: List of Chatoyant Rocks
14. RE: List of Chatoyant Rocks
15. RE: List of Chatoyant Rocks
16. RE: List of Chatoyant Rocks
17. RE: List of Chatoyant Rocks
18. RE: List of Chatoyant Rocks
19. Re: Cutting Dop Sticks
20. RE: Cutting Dop Sticks
21. RE: Need Source for Pulley, Belt and Arbor
22. RE: Flashes of Light when Cutting with SiC
23. RE: Flashes of Light when Cutting with SiC
24. RE: Flashes of Light when Cutting with SiC
25. RE: Learning Tumbling at Home


Subject: LapDigest News for Issue No 241 -Thurs 10/21/1999

..We are really growing!! webbie has a statement that they serve
20,000 rockhounds per month. With 1820 members presently
on our list, and putting out 2-1/2 issues per week, we send
out 19565 newsletters a month!!! WOW!!! I never realized
the number was so large!! And that doesn't count the
website hits or the files distributed from the server

..And we have growing pains!!

Note the large number of items we have in this issue. We had
a total of thirty-something, and I had some which I did not
run for one good reason or another. Two solutions to this
overcrowding problem: put out the Digest more often - or -
restrict the types of messages we accept. Now. we accept the
following types:.. queries on lapidary methods, techniques,
materials, .. responses to queries, announcements,
.BIOS, .. for sales, .. want to buys. Which ones do you
think we can eliminate, in order of your priorities? Or, if
not eliminate, give a low priority to. Write and tell me.
If you have any other ideas for controlling size, I' like to
hear them, too. Write me at

Also, putting out the Digest more often is not an option!!

Spent a lot of this past week putting together a list of
phenomenal stones, which I will publish in the next Digest;
it should be out on November 2 or 3.

Well, I'm going down to William Holland School for the next
week to take Joe DePetrie's class in opals again; he really
knows about healing cracks in opals, etc., so I'm gonna
take good notes and tell you what he said.

Hopefully. the NC mountains will be beautiful this time of
year. I went to Highlands 51 years ago today on our honey-
moon, and we awoke to find 3" of snow covering the ground!
It was beautiful. We played in the snow and had a barrel
of FUN!!! Y'all do, too!!


Subject: New: 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. The sump holds about 5
gallons. I was thinking of adding some blocks in the sump
to bring up the level if you think it needs to be raised or
adding one of the oil based coolants discussed in the other

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



Subject: NEW: Need Part for Hillquist Saw

We need an oil reservoir for a 24 inch Hillquist saw. Does
anyone still supply parts for this saw?

I could not find any more data on it, i.e., no Serial Number
or Model Number.

Carl DeMuth

Subject: NEW: Instructions for Overhead Arm Polishing Unit


I recently acquired a Highland Park Model SP-1 overhead arm
polishing unit. It had no instructions. Is the metal head
to be used directly on the stone with grit. If so, is some
sort of leather bonnet used for the final finish?

Anyone who can shed some light on how this is used will be
most appreciated.

Larry Bruce

Subject: RE: What Adhesive to Attach Rock to Wood

<<Any ideas on using an alternative adhesive?>>

Hi Hale,

First, cut the wood so you have a fresh clean joint. Then
clean the rock with hot water and soap, and let it dry
thoroughly. Lay the rock so the surface you want to stick
to is facing up. Soak the surface of the stone with a good
grade of epoxy and lay a piece of medium weight fiberglass
cloth in the wet epoxy. Saturate the cloth and place the
wood piece in position. Let it cure and you have a joint...

Bob Braun

Subject: RE: What Adhesive to Attach Rock to Wood

I was advised to use BONDO auto body filler. It works.

Jesse Brennan

Subject: RE: What Adhesive to Attach Rock to Wood

Try adding one more thing to your tip of using white glue
(Elmer’s). Place a piece of newspaper between the rock and
the wood. Be sure to apply the glue to both sides of the
paper. Like you say, you can soak the wood from the rock!!

Don Sommerfield

Subject: RE: What Adhesive to Attach Rock to Wood

I have been gluing rock halves to wood blocks for some 30
years with Elmer's or carpenter's glue usually purchased in
gallon jugs. Scrap plywood in 5/8" or 3/4" thickness is
preferred and the glue is allowed to dry overnight. Scrap
wood is plentiful here at house construction sites or in
residential areas on trash pickup days.

Lou Harms, Independence, MO

Subject: RE: List of Chatoyant Rocks

Hi Hale,

How about the sheen obsidians?


Subject: RE: List of Chatoyant Rocks

I believe there is a cat's eye chrysoberyl. Also, would
color change ( i.e.; Alexandrite ) material count?

1 Lucky Texan

Subject: RE: List of Chatoyant Rocks

How about the various 'sheen' and 'rainbow' obsidians.

Subject: RE: List of Chatoyant Rocks

Hale, you can add Alexandrite and jade to your list as I
have strong catseye cabs of each.


Bob Boston

Subject: RE: List of Chatoyant Rocks

Beryl of all sorts, I'm assuming. I have green chatoyant
and blue chatoyant and I have certainly seen emerald. I'm
assuming the other colors.


Subject: RE: List of Chatoyant Rocks


I agree with your definitions, but you're forgetting the
*original* chatoyant stone: chrysoberyl.

When the term "cat's-eye" is used in the jewelry trade it
means only one thing: cat's-eye chrysoberyl. (Attached is
a jpeg of a large, fine stone now in my possession: 14.49
carats of pure beauty! Shadows make the stone seem
asymmetrical in the pic but it's perfectly cut.)
Chrysoberyl has been synonymous with cat's-eye for hundreds
of years.

Lately I've been cutting some very nice cat's-eye stones
from another form of chrysoberyl, Alexandrite, the rarest
of the rare -- I have some small rough available if anyone's
interested. (A jpeg also attached: this stone is .83 ct.
and has a decent color change).

I've cut lots of star garnets (usually almandine but I've
seen rhodolite stars, too). Color play in opals is
considered "phenomenal." I've also cut stars and cat's-eyes
from Spencer, Idaho opal (triplets).

Liddicoat offers additional stones that can exhibit
phenomena in his "Handbook of Gem Identification."

Stars or cat's-eye effect: beryl, demantoid, nephrite,
enstatite, diopside, scapolite, kornerupine, feldspars,
apatite, zircon, sillimanite, as well as chrysoberyl,
corundum, quartz and tourmaline.

"Orient" in pearls is also considered phenomenal, so I
imagine abalone shell and abalone pearls would also fall
into the same category, along with mother of pearl, etc.

How about sheen and rainbow colors in obsidian? Fire agate?
I'm getting tired. Time to go have a cold one and think on

Rick Martin
"Richard O. Martin" <>

Attachment Converted: "c:\eudora\attach\Mvc-708f.jpg"

Attachment Converted: "c:\eudora\attach\Mvc-655f copy.jpg"


Subject: RE: List of Chatoyant Rocks

Please add Chatoyant Bowenite (Tangiwai) and Chatoyant
Nephrite Jade (Greenstone, or Pounamu [called by the
Tangata Whenua]).

Just thought I'd introduce a bit of Maori culture here.

>From New Zealand:

Craig McGregor

Subject: RE: List of Chatoyant Rocks

Add Binghamite and Silkstone to the list of chatoyant
stones. Locality closed (due to flooding?)

If we're including man-made stones, add Victoria Stone; a
chatoyant glass minerologically similar to nephrite.
Hardness 5.5-6.0, colored azure blue, deep indigo, lemon
yellow, brownish pink, chocolate brown etc. Invented by
Dr S. Iimori and made by himself and his family.

My untrustworty brain reports that the recipe or process
has been lost but I cannot find a reference.

For a description see LJ Aug 1969 and for working
instructions see LJ Dec 1980


Subject: RE: List of Chatoyant Rocks

G'day Hale,

I note that the list doesn't include one of my specimen
cabinet favourites: chatoyant agate.

In the States I see that it's usually called 'shadow' agate,
or referred to as displaying 'parallax', but here in
Australia (or in Tasmania, at least) I more usually hear it
referred to as displaying chatoyancy.

Whether or not it is real chatoyancy by definition is a moot
point, because rather than a play of light off fibres, it is
more an interplay of light between tightly-packed
alternating opaque and transparent agate bands, activated by
rocking or tilting the banding to and fro to admit light
into the clear spaces between the opaque.

I'm probably not telling anyone anything new, but for those
unfamiliar with the phenomenon, it is not unlike bobbing up
and down in front of open venetian blinds... probably right
now there are several thousand people around the world doing
just that !)

Beyond Australia I've seen magnificent examples of shadow
in Mexican Lagunas, Lakers and Scottish agates.

Here in Oz, the green/yellow variety of shadow agate from
Agate Creek, Queensland, is justly famous, and even moreso
when the shadow banding is actually comprised of the tiny
yellow dots known as 'goldfleck'.

Less well known is the pink and clear shadow agate from Wave
Hill in the Northern Territory, and the black/gray/white
shadow agate from the Lune River gemfield in southern
Tasmania, which can be very spectacular.

I have a limited amount of trade in these if there are any
other shadow agate collectors out there...

Thank you, Hale, for the Digest. It enriches living on the
edge of the wilderness in this island at the end of the

Phill Mason

Subject: RE: List of Chatoyant Rocks

("Marra Mamba" Tiger Eye)

Hale, there was a question about "Marra Mamba" tiger eye
from Australia in the digest and I have the information
about it.

Marra Mamba tiger eye is one of Australia's most
beautiful semiprecious gemstones. The richly colored and
highly chatoyant material was mined from isolated pockets in
the blue crocidolite seams at a small deposit in the rugged
Hamersley Ranges of North Western Australia. The deposit is
the only source for this gemstone in the world, and is now
mined out.

The name "Marra Mamba" is taken from the geological banded
iron formation in which the Tiger Eye occurs, and which
outcrops extensively throughout the Pibara region. The
gemstone was formed hundreds of millions of years ago
during the Volcanic Era when the Hamersley Ranges were
being formed, by highly mineralized silica impregnating the
crocidolite fibers.

The Tiger Eye is enclosed in an attractive jasperlite host
rock, through which a lace-work of hematite banding occurs
together with splashes of iron pyrite, giving the stone its
unique characteristics.

The cost of this material, if it can be found, usually
starts at $100.00 per pound rough and is sold by the gram
in smaller lots. The finished cab can bring $75.00 & up.
To a truly avid collector there is no other stone that can
compare to "Marra Mamba" tiger eye.


Subject: Re: Cutting Dop Sticks

I have an interesting way of cutting dop sticks. I go to a
lumber yard and purchase the dowel sticks. I ask them if
they will cut them for me, and usually they will. It is
free at most major lumber yards (i.e. Home Depot, Eagle
Hardware, etc.). They usually have a power miter saw set
up and it takes them only a minute to turn a 3' dowel into
many 5" dop sticks. As Hale said, I never worry about
them being perfectly square as the wax will make up the
minor differences.

Randy R. Aue
Estes Park, CO 80517

Subject: RE: Cutting Dop Sticks

I have to agree with Hale that a dopstick doesn't need to
be square since you have to pay attention to position while
the wax is cooling.

Since I'm not worried about the squareness of the cut, I've
stopped cutting them at all, and now purchase preformed
wood dowels at a furniture manufacturer's outlet store in
my town. They have a little taper at the end and are not
precisely cut, but they only cost 2 or 3 cents apiece.

The dowels come in assorted diameters and are not as long
as you usually see dop sticks, but I've adapted (aDOPted??)
and found that I prefer the short stick.

Chunk Kiesling

Subject: RE: Need Source for Pulley, Belt and Arbor

If you're looking for a particular set of belts and pulleys
for a certain piece of equipment (arbor), we have them, but
not on the web site.

Otherwise go to your local hardware store (you can get them
for less there). You can reach us at 1 (800) 820-3612.


Subject: RE: Flashes of Light when Cutting with SiC

Al (and Hale),

The production of light by pressure is called
triboluminescence. You can demonstrate this with sphalerite
or corundum crystals by stroking them with a metal point in
darkness. Sugar also shows the effect, which can be
demonstrated with pop-o-mint 'lifesavers' or rock candy;
crush with hammer or jaws in darkness (take a mirror into
the closet and chew lifesavers with your mouth open). My
Peterson Field Guide mentions that this effect is often
seen when sawing rock crystals.

But I agree, if you start seeing sparks when sawing you are
probably pushing too hard and need to ease-up/slow-down
(same for grinding).

Kreigh Tomaszewski
Please visit our family web pages at

Subject: RE: Flashes of Light when Cutting with SiC

There are a number of materials which, when stressed give
out light as well as heat or an electric charge. A variety
of quartz materials do this, such as agate, amethyst,
chalcedony etc.

Try this harmless experiment. Stand before a mirror in a
very dark room, place a lump of sugar in your mouth and
with your mouth open - crunch! Your whole mouth will
momentarily light up with blue light. Er - harmless? well,
so long as you clean your teeth after the sugar!


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


Subject: RE: Flashes of Light when Cutting with SiC

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. My grandkids get a real bang out of smacking
rocks together out on the porch to see which ones will make

I suspect something in the composition of the wheel (the
carbide?) is acting like a striker although the spark is
very, very small.


Subject: RE: Learning Tumbling at Home

Tumbling at home is fairly simple.

Step 1
Find rocks that are approximately the same size, no bigger
than a quarter, usually does the trick.

Step 2
Fill the tumbler to about 2/3 capacity.
For each step fill the tumbler to just about cover the
rocks, but not quite, with water.

Step 3
If stones are broken, use a 46/70 grit for 1 week and wash
thoroughly; if stones are round river tumbled, go directly
to Step 4.

Step 4
Tumble with 100/120 grit for 1 week and repeat wash
thoroughly. I like a tooth brush to scrub the little
cracks. If stones still have a crevice in them after Step
3, break them and re run them in the 46/70 grit.

Step 5
Use a pre-polish and 1/3 cup dish soap for 4-5 days.

Step 6
Use polish 4-5 days or up to 1 week .

Step 7 Use 1 cup liquid dish soap for about 3-4 days.

Your stones should come out sparkling!
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