LAPIDARY DIGEST
Administered by Hale Sweeny (hale2@mindspring.com)
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This list digest contains the following message subjects:

1. LapDigest News - Issue No. 23 July 11, 1997
2. NEW: Polishing Mother of Pearl
3. NEW: Polishing a star ruby
4. RE:Are There Hand Methods for Lapidary Work?
5. Re:Tumble Finishing Cabs with a Vibrasonic Vibratory Tumbler.
6. RE: Change in Opals Colors over Time
7. RE: Change in Opals Colors over Time
8. Re: How do I cut a base at an angle?


<MSG1>
Date: Fri, 11 Jul 1997
Subject: LapDigest News - Issue No. 23 July 11, 1997

Hey gang, please look at the tumbling list from yesterday, and send names and authors of any tumbling books you know about which are not on the list.

I want to build lists of reference material to put in the archives, and this list of tumbling books is the first book file.

And look around to see if any of you have any TIPS you might send for fillers on news-poor days!

hale
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<MSG2>
Date: Fri, 11 Jul 1997
From: hale2@mindspring.com

Subject: NEW: Polishing Mother of Pearl

A friend in Illinois, Sherry Maves, wrote to me:

----------
Do you know what will polish mother of pearl?

I found some incredibly beautiful clam shells on the Mississippi
River, which look like something out of a tropical ocean, not a river!
I found 15 large ones, still hinged, and I think I must have 5 different species, judging by their appearance.

I've never done any lapidary stuff, but Geri showed me how to use the grinders, etc. and I cut a heart for a pendant and a tear drop shape
from one of the shells. THey are so neat....and I was so proud of
myself! :)

Someone told me there is a jeweler's polish of some sort that would make
them really shine, but I don't know what it is. Thought you might know.
I really want to go back for some more shells..just love them.
-----------

Well, how about it, gang? Anyone want to help this lapidary neophyte
by discussing any aspects of cutting and polishing shells?

hale
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<MSG3>
Date: Fri, 11 Jul 1997
From: ron@osglink.orionlink.net

Subject: NEW: Polishing a star ruby


Hello all,

I'd like to know what is used for a final polish on a star ruby.

Also thanks for the help on the opals.

Ron
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<MSG4>
DATE: Thursday, July 10, 1997 11:06 AM
FROM: Etzwiler, Rusty <Rusty.Etzwiler@PSS.Boeing.com>

SUBJECT: RE:Are There Hand Methods for Lapidary Work?

My thanks to one and all who took the time to answer my question. Some
of the answers were new ideas for me and others reminded me of something
I knew or had read, but had forgotten. The url sent by Bob Foster was
delightful reading! Again, my thanks.

I have been asked to describe the Lortone TM Stroker Hand Cabbing
System. It consists of a plastic tray approximately 3 x 8 inches with
dowel-sized grooves down each side. The silicon carbide (carborundum)
sanding screens are placed over the top of the tray overlapping the
sides and held in place by dowels (plastic ones in the kit) placed over
the screening in the side grooves and tensioned with big rubber bands.
The kit contains coarse, medium and fine sanding screens (I found
replacement material at a local hardware store - Silicon carbide
sheetrock sanding sheets.), pre-polish, polish, polish cloths, file
board (emery board) two plastic dop sticks with double-sided tape (not a
particularly satisfactory method of holding a stone to a dop), and
instructions. I think this kit was originally designed for youngsters
but works for anyone who wants to spend the time to work a stone by
hand. I saw a young girl working with one of these kits at a local gem
and mineral show and watched the dealer tables at the various shows in
our area until I saw one to get for myself. I think Alpha Supply in
Bremerton, WA was the dealer who finally had it on his table at a show.

I have added to this kit several grades of wet/dry sand paper from my
local hardware store for finer sanding and I dip my stones in a small
bowl of water frequently to both wash the sanding residue off the stone
so I can see where I am and to provide a medium for the grit to do its
work.

It's much slower than power equipment, but I'm not doing production work
and I can work a stone virtually anywhere.

Rusty Etzwiler
(425) 865-4211
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<MSG5>
Date: Thu, 10 Jul 1997
From: Vybtl@aol.com

Subject: Re:Tumble Finishing Cabs with a Vibrasonic Vibratory Tumbler.


Hi John:

Once again I find myself looking for understanding. In your excellent piece
explaining the process of using the vibratory tumbler to finish cabs, you
mentioned something that struck me. Your use of a filler to bring the
content level up to 3/4 full. What type of decline in action do you see
should the level be below that? Reason is there's been a couple of runs put
through the unit that were less than 1/4 full with carrier shards in place.
Results were very good. From a business standpoint, this was pretty stupid
on my part, but I do have that inate ability to justify my idiocies.
The attraction of the vibratory tumbler is the simple fact that one is not
regulated so strictly by the quantity of content in the hopper, unlike rotary
type, to produce the required grinding/polishing action. The decrease in
time needed to process material through these types of units is also a plus,
when compared to it's predecessor. Guess the question is has your experience
with this type of tumbler shown best results when hopper is filled to
approximate capacity?

Thanks in advance

Vince
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<MSG6>
Date: Thu, 10 Jul 1997
From: daves@sunline.net

Subject: RE: Change in Opals Colors over Time


In LapDigest #22, Bob Foster asks:

<<Does hydrophanous opal ever have fire, and is it ever mixed with regular
opal in the same stone?>>


Yes, at least to the first part. I've had hydrophanous (neat word) opal
that was clear and had color when wet and was plain colorless white when
dry. I've also had it where the color only appears when dry. (some of the
Louisiana Swamp Opal colors when dry)

To test for hydrophanous properties, touch the stone to your tongue. If it
feels sticky....it's hydrophane.

Has anyone tried to stabilize hydrophanous with Opticon? Wonder if it
would work?

Dave

I think I'll name a daughter Hydrophanous.
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(Ed. Note: Not knowing the term 'hydrophane', I looked it up in MINERALOGY
by Sinkankas 1964, p447. Here is what I found:

.hydrophane (opals) are white, opaque, or barely translucent porous kinds
which absorb considerable water; if the material becomes translucent after
soaking, it is called hydrophane; the latter may or may not also show play
of color.)
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<MSG7>
Date: Fri, 11 Jul 1997
From: bova@bovagems.com

Subject: RE: Change in Opals Colors over Time


Hi All,
Just got several ounces of Mexican fire opal on and off matrix, and some
hydrophane from a sale at the Opal Society last night. It's from a
lifetime collection that was donated to the Society, and includes some
pretty wild stuff! I have some that looks like hydrophane and fire opal,
with and without play of color, in the same stone.

Some look like they formed almost like concretions, with one thick layer
wrapping around another, in almost round pieces. And I have a couple of
pieces where the center is opaque and grades into an outer layer which
is red fire opal. Have to wait and see if it turns out to be all
hydrophane, but doesn't look it so far. We've been told it can take up
to a year for all the excess water to dry out, and they've only been
drying 3 months. So I don't know how much is stable and how much will
craze. But it's fascinating material.

It looks like in drying, the red layer frequently breaks off from the
inner, opaque, pale peachy color, but that might just be the way it was
mined. Will know more in a few months.

In the meantime, any advice on free form carving Mexican opal?
Carol
.------------------------------------.
| Carol J. Bova bova@bovagems.com |
| Gem Sales and Auction Coming Soon! |
| The Eclectic Lapidary e-zine |
| http://www.bovagems.com/eclectic/ |
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<MSG8>
Date: Thu, 10 Jul 1997
From: gary.ogg@worldnet.att.net

Subject: Re: How do I cut a base at an angle?


The wood wedge is a good suggestion. If the rock is 4x4x6 and you use
only one wedge, place it underneath the rock at the end farthest from the
blade. This will allow your vice to clamp solidly on the sides of the rock.
If this lifts the front edge above the top of the saw blade you should use
two blocks placed on opposite sides of the rock to maintain solid clamping.
The wedges should be 3 to 4 in. long and almost as wide as the rock.

Gary Ogg
Columbia, SC
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