(TP) My interest is meteorites under the microscope. I
noticed many thin section cross polarized light micrographs in books
but no high magnification reflected light micrographs of polished
samples.
|
This is an example of a barred chondrule found in a thin
section of JaH 055 viewed in cross polarized transmitted
light. |
This area really captured my attention as these methods show what
the meteorite actually looks like close up. While beautiful and
necessary for classification, cross polarized light examination of
thin sections hardly resemble anything familiar to anyone but a
highly trained viewer.
|
This is also an example of a barred chondrule found in a
polished slice of JaH 055 viewed in incident (Reflected)
cross polarized light. Ever wonder what it looks like
between the lines of a barred chondrule? Notice the
difference in the image using the two very different
methods! |
(MT)
Does your Family share in your interest in meteorites?
(TP) My family loves the irons and pallasites. They don't
share my enthusiasm for stones and can't understand why I will get
so fired up over an apparent piece of gravel.
|
Way up close (600X) of Brahin Pallasite. Polished slice
in reflected light. |
(MT)
Do you have
any special approaches to collecting? (Type collection, only stones,
only irons, only by aesthetics, etc. or any and all that you like.)
(TP) It is my long term goal to have representative
micrographs of all meteorite classifications. As I need only about
a 1/2gr. piece to polish and examine, my collection of "micros" is
growing.
(MT)
Do you mind
saying how many locations your collection represents?
(TP) If I count thin sections and micros. a little over 200.
(MT)
Is your
collection displayed or kept in a dry box or both?
(TP) I have a large quantity of unclassified NWA because it
provides me with an affordable quantity of meteorites giving me
plenty of material to explore and perhaps make discoveries.
Meteorite collectors may remember the photo of Dean Bessy laying
atop a pile of large NWA. I bought that collection from Dean and
many of those decorate the area around my microscopes.
(MT)
In what ways
do you use your computer for meteorites?
(TP) Without the computer, I would of never built a
collection or obtained any of my microscope equipment.
The zoom condenser allows focus of the light
source as well as the objective. Details of
the fracture lines lying between the
thickness of a 30 micron thin section were
not so vivid without this condenser.
|
The aus Jena (East German Zeiss) Co. made a revolving aplanatic 'pancratic'
(zoom) condenser where the NA is continually variable between 0.16
and 1.4 for their research microscopes. Only a very few were made
because of high costs. Because of the computer (and eBay) I was
able to obtain one from Beijing China. It really gives my thin
section Xpol shots some "POP".
(MT)
Do you ever
hunt for meteorites?
(TP) All the time! My family gets tired of me stopping the
car to check out a rock.
I've spent a tremendous amount of days hiking with a magnet on a
stick. I like to walk to fast for a metal detector. After digging
up a few hundred bullets and nails you want to just walk and look
for rocks. I have set out to find a new strewn field but so far the
only find I have made was in the known strewn field of Gold Basin
Arizona.
(MT)
What is your
favorite meteorite in your collection?
This micrograph shows the unusual structure
found in a polished slice off the 12 Kilo
NWA.
|
(TP) A large 12 Kilogram oriented Unclassified NWA. I
couldn't stand it and I cut off a small slice. I wasn't
disappointed. It has some unusual microscopic structures that I
haven't seen in other meteorites. I have not yet had it classified.
(MT)
What is your
favorite overall if it is not the one above and what makes these of
special interest?
(TP) Flat out-SaU 001. Sayh al Uhaymir, an ordinary
chondrite L4/5 found in the country of Oman in 2000 with a estimated
total known weight of over 400 Kilograms. This meteorite not
only has a beautiful exterior and interior, it is the most
interesting and surprising on the microscope.
This 1030 gr. SaU 001 individual nicely
shows the copper metallic finish some of
these meteorites exhibit.
|
Prime SaU 001's exhibit a beautiful copper metallic finish that
almost looks applied. I think this finish comes from the
vaporization of interior metals but others suggest it is part of the
weathering process.
Given it's large TKW and it's inauspicious classification, it is
affordable to every one even in an impressive size.
(MT)
What
meteorites are currently on your wish list?
(TP) After talking for hours with Martin Horejsi about
historic witnessed falls, I realized that while I have some cool
rocks, I don't have a single one with a pedigree. He may have
gotten me hooked on a new direction in meteorites.
(MT)
What methods
have been most successful in building your collection? (Buying at
shows, from dealers by mail, auctions on the web, trading... etc)
(TP) Almost entirely with contacts made on eBay and continued
from there. Make friends and they may offer it to you first!
(MT)
Do you also
collect related materials like impact glasses, breccias, melts,
tektites, shocked fossils, native iron rocks etc?
(TP) I have just a representative amount of tektites,
minerals and fossils however, my driveway is lined with meteorwrongs
I carried home to check into.
(MT)
Do you
prepare any of your own specimens? (cut, polish, etch, etc.)
(TP) Yes, I have 4 saws with different size/thickness blades,
3 Lap machines and a Struers thin section production machine. I
polish the specimens in a 7 step process, finishing with a 1/4
micron diamond slurry. This level of polish is necessary for
microscope viewing.
(MT)
Have you had
to take any special measures to protect them from the environment?
(TP) I live in a fairly dry area so humidity caused rust is
not a bad problem. I have found however, that a polished face can
be nicely protected with a hardwood floor paste wax. This
treatment not only protects from rust, it does so with out effecting
the microscopic viewing. In fact, this treatment allows for easier
photography of the specimen. Note: this only works on polished
slices. It looks awful on a rough cut/grind.
(MT)
What type of
special equipment have you acquired as a result of your 'e meteorite
hobby?
(TP) My microscopes and lapidary machines.
These are my primary microscopes. An aus
Jena Neophot 21 and Fluoval.
|
This is an example of the specimen
preparation equipment I use.
|
I have numerous microscopes but have fine tuned an aus Jena Neophot
21 for incident light viewing of polished specimens and an aus Jena
Fluoval for thin section viewing.
(MT)
What part of the meteorite hobby gives you the most satisfaction?
(TP) I like to give myself personal challenges. After
getting up to speed in reflected light microscopy I took on cross
polarized light thin section examination and from there, thin
section examination in combined transmitted and incident cross
polarized light.
-029.jpg)
An example of combined incident and
transmitted cross polarized light. It is
taken of a DAG 478 (L6) thin section.
|
I even worked on darkfield examination. Darkfield techniques didn't
prove useful in meteorite examination but at least I gave it a try.
An unfortunate housefly taken in darkfield
(Phase contrast)
Please Note: The house
fly was a house fly slide. Part of a child's
"Insects under the microscope" set.
|
(MT)
Who influenced you the most in meteorites?
(TP) This is my favorite question as there are so many great
people attracted to this hobby. In order of occurrence:
Bob Haag: I carried his catalogue with me like it was a "Life
Guide". He was the first person to give me confidence in my
micrographs. It was Bob who connected me to Joel Schiff, then
editor of Meteorite Magazine.
Joel Schiff: Although I was a nobody in the meteorite world, Joel
took a chance on me and helped me write my first meteorite article.
He even put one of my micrographs on the cover of Meteorite
Magazine.
Rob Wesel: Most of you know him as Nakhla Dog. Rob was the first
person to treat my micrographs as a valuable asset. He sent me the
coolest material I had ever seen (he comes up with some amazing
material) and would let me keep the sample in an exchange for a CD
of micrographs.
He even sent me a 5 kilogram Urelite to examine, but sadly, I had to
return that one. I still have a sense of pride when I go to his
site and see my micrographs.
Martin Horejsi: I am amazed at his knowledge of meteorites. Not
just the scientific side of structure, formation processes and
chemical composition, but the stories behind the meteorites. We
have spent days cutting and polishing meteorites (I am always trying
to talk him into taking an other one of his historic meteorites to
the saw).
Martin has mentored me in the scientific process. He has the most
analytical approach to meteorites and I hope to learn a lot more
from him. My approach has always been trial and error (is it hard?
"I don't know. Hit it with a big hammer.") While Martin is amused
at this, he always takes his time and determines the right way.
Cutting and grinding rocks for hours is hard work and you learn a
lot about someone doing it with them.
He won't boast, but I swear he can correctly guess a meteorites
classification just by giving him a magnet and a jeweler's loop.
(MT)
Do you have any favorite micrographs?
(TP) Yes there are two. The first was used on the cover of
Kevin Kichinka's book The Art of Collecting Meteorites. This
micrograph of an SaU 001 chondrule? appears to have intertwined
tendrils rather than typical barred chondrules.
This micrograph of an unusual chondrule?
seems to look almost organic. Found in a
polished slice of SaU 001.
|
The other is an unusual crystal structure I found in a slice of JaH
055. An ordinary chondrite, this structure is any thing but
ordinary.
Unusual structure found in a slice of JaH
055.
|
