Blue Tiger's Eye
Nick Prince
rough. Last weekend I decided to polish a piece to see how it would
turn out. To be honest I was disappointed. While it "felt" like a great
polish (the sample was very soft to the touch and the blue bands were
much more noticable) it never got the polish I have seen on tumbled golden
tiger's eye. I used a Fordam (sp?) tool with wood dowels starting at 180
diamond paste and worked my way through to Cerium (180, 300, 600, 1200,
cerium). I am still very new to all of this so I'm quite willing for
the problem to be my technique. I have three questions:
1. Was my described technique correct?
2. Is there really such a thing as blue tiger's eye?
3. If there is will it ever shine up the way golden does?
Thanks in advance.
Nick
John F. Miller
>I would like some help. Recently bought some slab cut blue tiger's eye
>rough. Last weekend I decided to polish a piece to see how it would
>turn out. To be honest I was disappointed. While it "felt" like a great
>polish (the sample was very soft to the touch and the blue bands were
>much more noticable) it never got the polish I have seen on tumbled golden
>tiger's eye. I used a Fordam (sp?) tool with wood dowels starting at 180
>diamond paste and worked my way through to Cerium (180, 300, 600, 1200,
>cerium). I am still very new to all of this so I'm quite willing for
>the problem to be my technique. I have three questions:
>1. Was my described technique correct?
Basically yes, but polishing many materials can be problematic. In this
case, alumina might do better than cerium oxide, but you might want to
use diamond - maybe 8000 and then 50,000. I think a lot of cutters just
use diamond for everything these days. I don't. Experiment a bit with
different polishing methods.
>2. Is there really such a thing as blue tiger's eye?
Yes -- it's also called hawk's-eye.
>3. If there is will it ever shine up the way golden does?
Maybe -- it depends on the material itself. Your material may be a
little softer and more friable, in which case it may never give quite
as good a polish.
John Miller
G. Flores
> 1. Was my described technique correct?
> 2. Is there really such a thing as blue tiger's eye?
> 3. If there is will it ever shine up the way golden does?
Blue tigerseye definitely does exist, I think the classification is
based on whether a stone has the same "chatoyant fibrous inclusions"
which are aligned in the same direction that result in the
characteristic "sheen" of tigerseye.
I forget how many different colors of tigereye there are, although
technically, only the gold color is called tigereye. Red tiger eye
is created by heating gold tigereye. Blue tigereye is actually
called "Falcon Eye" (I think), and there's also something called "Ox
Eye" (dark brown?).
As far as polishing, your steps seems fine to me. Because of the
background, blue tigerseye doesn't seem to give off as much
brilliant glow as the gold does. I think the surface of a
well-polished blue stone should be perfectly smooth and have deep,
lustrous quality, rather than a sharper reflective quality. The only
real problem I've seen with polishing tigerseye in general is that
sometimes both blue and gold tigerseye have what seems like
capillary holes in the surface. When you get to a final polish
stage, these small holes fill up with grit and junk. They make your
stone look terrible and can only be gotten out with serious
grinding.
Hope this helps
GF
Curt Gates
Flores) wrote:
> In article <atluserD...@netcom.com> atl...@netcom.com (Nick Prince) writes:
>
> > 1. Was my described technique correct?
>
> > 2. Is there really such a thing as blue tiger's eye?
>
> > 3. If there is will it ever shine up the way golden does?
I apologise for jumping into the middle of a thread, but I somehow missed
the start. I used to get large (80 pound) sacks of tigereye rough from a
fellow who was a radio operator in the merchant marine and brought these
sacks back on his ship. The material consisted of heels and trimmings from
a factory in Africa. Considered scrap for a commercial production, but
great for a custom cutter. Most of the material was golden. There was some
blue. And also some natural red, which often blended with the gold.
I may get flamed for this, but I believe tigereye is essentially petrified
asbestos, and I use those two terms loosely. Its a fiberous mineral like
asbestos that has been replaced, fully or partially, by silica. If the
replacement has been complete, the material is solid and cuts and polishes
easily. If the replacement is not as complete, the fiber structure can
cause problems. Which is why the old rule about grinding perpendicular to
the fibers (to keep from pulling them out) and then polishing parallel to
them. Apparently, the blue material is closer to the original fiberous
material and a larger percentage can be harder to work (less silica). But,
yes, with good rough, you can get as good a polish on the blue as the gold
and the red (except if the red was heat treated and not done well). With
poor rough, it is nearly impossible to get good results.
I missed your technique, but if you do your sanding with diamond compound
and then do the final polish with tin oxide on leather, or felt, you can
get a perfect polish. You can have a lot of fun if you try for different
orientations other than the one parallel to the fiber structure, which
gives you the eye effect. Quite a few of the trimmings were from the edge
of a seam, and would produce scenic material somewhat like picture jasper.
Like what you often see in what is called tiger iron.
Nick Prince
: I would like some help. Recently bought some slab cut blue tiger's eye
Megan Farley
on it similar to golden tiger's eye. I know that this must be
possible. Keep trying.
MILCRON
silicified Crocidilite. an asbestos-like ore. The blue stuff is much
less silicified than the gold and therefore more difficult to polish. I
pre-polish on a dry 600 grit belt 'till yhe stuff just about melts the dop
wax, let it cool and sand some more. I get 95 percent of the polish on
the 600. Make sure the previous sanding was perfect because the heat will
cause the top surface to "flow" over the scratches made on the 400 belt
preserving them for posterity. I finish with cerium. It is my
understanding that red tigereye is created when the miners use a
fire/quench technique to break larger masses of gold tigereye down to
smaller sizes. Tigereye mining is a "side-job" that is not done as a
regular venture. You can make your own red at home in the oven, I have.
Ron
John F. Miller
>Everythings seems to be moving in the correct direction here. Tigereye is
>silicified Crocidilite. an asbestos-like ore. The blue stuff is much
>less silicified than the gold and therefore more difficult to polish. I
>pre-polish on a dry 600 grit belt 'till yhe stuff just about melts the dop
>wax, let it cool and sand some more. I get 95 percent of the polish on
>the 600. Make sure the previous sanding was perfect because the heat will
>cause the top surface to "flow" over the scratches made on the 400 belt
>preserving them for posterity. I finish with cerium.
A WORD OF CAUTION! Be very cautious about dry sanding any stones!
The dust can be very hazardous to your health. Wear a good dust mask,
work in a well ventilated area, and clean up everything very well
afterward. As to the stone itself, heat builds up rapidly, and you'll
have to be careful not to overheat the stone and not to cool it off
too rapidly -- let it aircool and don't set it down on a conductive
material nor put it in water (rapid cooling may crack it).
With proper care, dry sanding can be useful on some stones (jade is
a good example), but play it safe!
John Miller
--
John Miller (John_...@unc.edu)
Department of Pharmacology, UNC-CH School of Medicine
1026A FLOB (231H) CB#7365, Chapel Hill, NC 27599 Tel: (919) 966-6966
G. Flores
> A WORD OF CAUTION! Be very cautious about dry sanding any stones!
> The dust can be very hazardous to your health. Wear a good dust mask,
This is good advice, but I recommend a respirator, not a dust
mask. Most dust masks I've seen are a joke. They don't seal properly
and so you are breathing in air from around the mask, and the
filters are usually primitive.
Respirators (I believe that's the official term) are much more
sophisticated units: they have a much better, tighter seal over your
mouth and nose and have infinitely better filtration. These masks
usually look like military gas masks. I bought mine for about $40
from Garret Wade (a Woodworking Supply company). They're expensive,
but so is a new pair of lungs.
Also essential if you're going to be doing this kind of work on a
regular basis is a decent dust collection system. Again, it means
shelling out bucks, but the long term health concerns make it more
than worthwhile.
GF
John F. Miller
G. Flores <gfl...@jc6813.mitchell.com> wrote:
>In article <3lu2dq$11...@bigblue.oit.unc.edu> j...@med.unc.edu (John F. Miller) writes:
>
>> A WORD OF CAUTION! Be very cautious about dry sanding any stones!
>> The dust can be very hazardous to your health. Wear a good dust mask,
>
>This is good advice, but I recommend a respirator, not a dust
>mask. Most dust masks I've seen are a joke. They don't seal properly
>and so you are breathing in air from around the mask, and the
>filters are usually primitive.
Good advice! My hasty comment about the dust hazard wasn't very
informative about the best solution, but just wanted to draw attention
to the problem. Certainly, a respirator and a ventilation system are
the way to go.