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This list digest contains the following message subjects:
1. LapDigest News for Issue No. 61 - Sun 9/21/97
2. NEW: Orienting Phenomenal Stones -
3. RE: Orienting Phenomenal Stones - Spectrolite
4. NEW: Is it Spectrolite?
5. NEW: Training and Certification to be a Judge
6. NEW: Buddstone
7. RE: Vibratory Lapping
8. RE: Refurbishing An Old Lapidary Machine (#60)
9. RE: Some Tumbling Questions (from Issue 60)
10. WTB: Rainbow Obsidian
11. WTB: Rainbow Obsidian
Subject: LapDigest News for Issue No. 61 - Sun 9/21/97
Just returned from Wildacres and a week studying intarsia
with the Magestros... Great class, beautiful mountains. What
more could one want? Well, a telephone connection and a
modem, for a start! (grin).
Hope all of you have been well. The next issue will probably
be sent on Wednesday 9/24.
Subject: NEW: Orienting Phenomenal Stones -
Hi guys --
Any advice on how to orient Phenomenal stones (cats eyes,
stars, and Labradorite/Spectrolite? I'm the one that did
the article on Canadian Spectrolite, which is fairly easy
to orient. The black stuff from Madagascar is much more
difficult. Any help would be appreciated.
(Ed. Note: I've changed the title a bit; to make the
threads which come from this query more useful, the name of
the stone being discussed will follow the title. Also, to
help get started, I've asked a friend, Goeff Houghton, [who
has a personal connection with Finland, and who knows more
about Spectrolite than anyone else I know.] to write a
little about Spectrolite, and he has done this below.
Anyone with special knowledge about orienting the other
stones - stars, cat's eyes etc., would you please share
your knowledge and experience by sending in a note with
the way to orient your stone? ...hale)
Subject: RE: Orienting Phenomenal Stones - Spectrolite
There seems to be confusion about the names "Labradorite"
and "Spectrolite". The following is what I believe to be
the truth: The mineral is labradorite, a member of the
common mineral group, plagioclase feldspar. The name
"Spectrolite" was coined for the gem quality labradorite
from Finland characterized by a black body color, which
yields particularly intense colors in the finished stone.
I believe it would be best if the word could be reserved
for the Finnish material.
The Discovery of Spectrolite
During the 1930's, a geological survey of Finland was
conducted. At that time, spectrolite was only known from
its occurrence in the glacial moraine at Lake Ladoga near
St. Petersburg, but the man in charge of the survey knew
that the glacier that had deposited the moraine had flowed
down from the north, through Karelia in eastern Finland.
He reasoned that the glacier must have gouged the
spectrolite from its mother-lode, somewhere in Karelia.
For several years, he and his family spent their vacations
and spare time looking for this mother-lode. They did not
In 1939, following the secret Molotov-Ribbentrop treaty
between Russia and Germany agreeing on how Europe should
be divided between them, Stalin demanded that the Baltic
states accept Russian "protection". Estonia, Latvia and
Lithuania, realizing that it was futile to resist, were
occupied without a struggle. The Finns told Stalin to go
to hell; they would not surrender their independence.
Russia invaded Finland.
This was the coldest winter on record, with a lot of snow.
The Russian army consisted of troops from the south and
east. They were dressed in brown uniforms, were not
trained to fight in the snow and could move only on the
roads. The Finnish soldiers were on skis, were dressed in
white and hard to see during the short, dark winter days.
Their strategy was to block the roads and attack the
stalled convoys from the surrounding forest. They were
highly successful and eventually forced the Russians to
The geologist's 18 year old son had joined the army and was
assigned to defense of the road from St. Petersburg to
Helsinki. When rocks were being blasted out to barricade
the road, he saw that they contained spectrolite. Happily,
he sent his father a note saying, "SPECTROLITE is to be
found in the parish of Ylymaa". Two days later, the
Russians arrived and he was killed in the fighting.
After the war, about 1950, the father traveled to the place
where his son had been killed and resumed his search for
the mother lode of spectrolite. This time he found and
mapped the six small deposits that are now known to exist.
The material is crystalline and the color is in one
particular plane of the crystal. Examine the piece
carefully and in a good light. Look for areas with fine,
parallel striations. These will be on relatively flat
surfaces. Even though they are not continuous, they will
be parallel throughout the crystal. The striations will
run along the side of a properly oriented slab and will be
parallel to the surface. Thus, the striations define the
edge of the optimal color plane. Grab the chunk between
finger and thumb lined up with the striations and, with a
light source overhead or slightly in front of you, rock
the stone back and forth using finger and thumb as a
pivot. The optimal plane is defined by the position where
you see the brightest color.
1. The color plane is just a few degrees off perpendicular
to the flat surfaces that carry the striations.
2. It gets easier with practice.
3. Let the stone be wet.
4. Grind or saw a small surface first, to see if you got
5. Watch out for crystal twinning; which is quite common.
The two twins have different color planes.
I hope this is useful.
**non-commercial reproduction permitted**
Subject: NEW: Is it Spectrolite?
At a gem show here in Columbus, OH last weekend, I bought
a piece of rough which is new to me. It's name (they said)
is "Spectrolite" and this piece is only about 2"x3"
It has a fine lamination structure, very regular, parallel
to the surface, sheet-like but saws on a trim saw like
ordinary "rock". It is translucent with a soft gray color
by transmitted light; however, when WET and held at the
proper angle to a point light source, it has a grand
display of brilliant multi-hued color, seeming to be in
phantom 3-D depth.
The color is, obviously, from interference or refraction
looking like oil slick(s) but from within the slab in
rolling waves. I would guess the surface is medium hard
.. ? 4-5.5 but I haven't been able to get much of a
polish to it (really haven't tried hard yet). Anyway,
smoothing the slab surface doesn't seem to help "see" the
color; rather, only having the slab totally wet (not just
spit and rub wet) reveals the iridescence.
I am a bit alarmed that the color intensity SEEMS diminished
after drying out for a few days. So, I am keeping it
immersed just in case. I would appreciate comments as to
what this is and what special handling might be required.
* George Butts, KC8T
* Laurie Butts, N8CKI
Subject: NEW: Training and Certification to be a Judge
The AFMS member federations provide for judging of
gemstones and lapidary work via competitive exhibiting. The
big problem has been the shortage of qualified judges and
uniform applications of the rules.
I just got back from Wildacres in Little Switzerland NC.
For those of you who don't know, the EFMLS offers lapidary
workshops twice a year, once in the spring and once in the
One of the classes offered is certified judging taught by
Jay Bowman and assisted by Pat Mummert. Jay is the Chair
for the AFMS Uniform Rules committee and a Certified Judge.
Pat is a former EFMLS President,former judge (she is now
blind) and with Jay wrote many of the books available on
competitive displays and judging. They are both wonderful
people to work with and present a very lively class.
The EFMLS is opening up the Judging class to ALL AFMS
federations to get more certified judges available
everywhere. Six seats will be made available on a first-
come first-served basis for each session to non-EFMLS
clubs in the AFMS. Applications will be available later in
the year and will be accepted starting January First.
If you want to find out what judges look for to be a better
cutter or exhibitor, or you want to be certified as a judge
TAKE THIS CLASS!
Feel free to contact me off list for more information. If
you are interested I'll be sure to get you an application.
Subject: NEW: Buddstone
I have a small slab of a material I have never seen before.
It is a pale lime green color with a swirl of white thru
it. There is a paper stuck to it with the name "BUDDSTONE"
written on it. There is no other information available. It
is a beautiful slab and I would like to know more about it
and where it may be obtained. Any information would be
Ed.'s Note: The name 'BUDDSTONE' is not mentioned in
Zeitner's GEM AND LAPIDARY MATERIALS. So I thought I'd be
clever and search the mineral data base for the color:
GREEN. Couldn't be too many minerals with that color,
right? WRONG!!! There were 715 minerals which came up as
having green as a color or a color modifier (e.g.:greenish).
I don't know about you, but I am surprised at this large
number! I think we may need more data, Bill, such as the
approximate hardness (such as fingernail, penny, knife blade
scratch test) Hope the members can do better at identifying
it than I did.. hale)
Subject: RE: Vibratory Lapping
Back at the computer and I see some of you are having some
problems with the Flat Vibratory Lap. Here are some things
that can go wrong:
Everything staying on one side---> Machine not level--->
(You should check the pan for level-- use a bubble level
so as to read it 4-ways at the same time.
Machines that have rubber balls for the pan to ride on -->
sometimes those balls are not the same size or those that
have cables they could be off. So when you level the unit
put the level in pan
Splashing--> Two things -->
(1) What you are trying to polish is too light --> add
more weight (I use up to 6 pounds of weight on some 6
(2 ) Grinding grit or polishing compounds are too wet.
(I keep my slurry just a little thinner than cream,
just so slabs will move freely.
You know you are polishing when you see all the slabs or
book ends rotating counterclockwise and moving clockwise
around the pan.
Hope this will help.
P O Box 6
Cle Elum WA. 98922-0006
Subject: RE: Refurbishing An Old Lapidary Machine (#60)
(Richard Dudley wrote in Issue 60 that he had inherited an
old Star Diamond cabbing unit which he wanted to refurbish,
and asked for advice.)
I don't know which machine you have. Some of the older
ones were a beast to do anything with. They involved
taking the belt, pulley and then pulling the shaft, in order
to change a wheel. If you have one of these, it may pay to
look for something that is easy to service.
If, on the other hand, wheels and expandable wheels can
come off without tearing everything apart, you can look for
parts. Grinding wheels are available through many sources.
Try (if you live in a larger city) to look in the phone book
under abrasives. If nothing is available locally, start
working the net. There are large differences in price. You
really have to look. Make sure they understand what you
want to use the wheels for. If the price is too high, you
may want to go to an 8 inch wheel. If money is no problem,
you may wish to add diamond wheels.
Let us know what type of machine you have and we may be able
to offer more advice.
Yea you can publish it or reprint it.
Ed. Note: I asked Richard for more info on the machine,
and he said it appeared to be a GP-6, based on a photo at
Dad's Rock Shop web site. He says: "The Unit has 1 8x3
expandable belt wheel, a 11/2 x 6 100 grit wheel, and a
11/2x6 220 grit wheel. They all need to be replaced."
Anyone else in the group with a Star Diamond GP-6 who may
be able to offer advice? Or, anyone else who has repainted
or rebuilt other old lapidary units, do you have advice
about cleaning, taking rust off, changing bearings,
repainting, and so on? If so, please help him. ..hale)
Subject: RE: Some Tumbling Questions (from Issue 60)
The type of grit I think he was refering to, which Wexler
called Wire Saw Grit, was used grit from grinding wheels.
I used to always recycle the grit that came off the
wheels in the grinding process. It took a little longer,
but worked well. When abrasives are graded close to a
given size the price goes up. This closely graded grit
is used for specific grinding type operations (in either
science or industry), where things are done to close
specification. In lapidary, we have lots of leeway and
can get away with using things that are close enough.
A tumbler may run 10 days. By that time things inside
are pretty much equaled out.
Yea you can publish it or reprint it.
Subject: RE: WTB: Rainbow Obsidian
Most of the rock shops in the west from Idaho to Mexico
will probably have some rainbow obsidian.
I visited the Discount Agate House in Tucson a couple
of years ago and was very impressed with their attitude.
They had several tons of obsidian there with some very
good rainbow as well as gold sheen, silver sheen, mahogany,
and snowflake obsidians. The fellow I saw out in the yard
filling orders was very selective in the rocks he selected
to fill orders. When I commented on it, he said he dosen't
like to send stuff to folks that he wouldn't be pleased to
recieve himself. He also had many kinds of agates and
He advertises in the Lapidary Journal and Rock and Gem
magazines. His address is : 3401 N. Dodge, Tucson, AZ 85716
Phone (520)323-0781 and his hours are Mon-Sat 09:30 - 5:30.
Hope this helps.
**NON-COMMERCIAL REPRODUCTION PERMITTED**
Subject: RE: WTB: Rainbow Obsidian
I just spent a few hours at the Denver Rock/Gem/Crazies
show- With all the rock I saw I would not be suprised if
the Mile High City sank a few feet from the weight!
I saw Rainbow Obsidian every time I turned around, most
from Mexico. It seemed that the best rough was not from
Mexico however. The prices I found ranged from $4 to
$7/pound depending more on quantity than quality. One
vendor who seemed to have nice rainbow material was Top
Gem Minerals, PO Box 50251 Tucson AZ 85703 ($4.50/pound)
I also found some mahogany obsidian at $2/# from another
University of Colorado Health Sciences Center,
Campus Box C234
4200 E 9th Ave Denver, CO 80262-0234
303-315-7225, FAX 303-315-6844
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