For larger images of these meteorites, follow the link in the left margin.
These first three images are all Sikhote-Alin meteorites. They all nicely display "thumbprints" or regmaglypts produced as they fell rapidly through Earth's atmosphere. Their rapid entry created heat that vaporized and eroded their surface.
Sikhote-Alin Mountains, Maritime Province, Russia. They are classified as coarsest octahedrite, chemical group IIB.
The Sikhote-Alin meteorite was at at 10:38 a.m. local time on February 12, 1947. Witnesses reported a fireball that was brighter than the sun. As it moved rapidly across the sky (at a speed estimated to be around 30,000 miles per hour) it created a smoke trail that lasted for hours. Records suggest that it may have been observed from as far away at 200 miles.
Typically meteorites entering Earth's atmosphere begin to break apart. The resulting onslaught of meteors (streaks of light in the sky) fell to Earth together to produce a strewn field of meteorites. Normally within the strewn field the largest fragments travel the greatest distance and the smaller ones trail off behind.
This particular strewn field covered an area about a half a square mile.
This
is another Sikhote-Alin that has been cut, polished and etched to show its very
coarse
crystalline structure.
This is yet another Sikhote-Alin showing a shearing structure created when the
fireball exploded or at impact.
This is
a NWA H5 meteorite showing many interesting chondrules. It is
believed that chondrules formed when our solar system was developing - some 4.5
to 5 billion years ago. They represent primitive, undifferentiated matter
associated with the solar nebula. The composition of chondrules can be
very complex with a wide variety of elements represented.
These are
Nandan (formerly Nantan) meteorites.
A
L'mahbas from Morocco, a stony meteorite. It is classified as a H6
Chondrite.
Jiquipillo Toluca Iron Meteorites.
H 5
meteorite from NWA
H 5 from
Morocco displaying a fusion crust.
Texas Stony
Meteorite
These three meteorites are from Gold Basin in Arizona. They are classified as L 4. The first specimen has been cut with a diamond saw to show the metal flakes associated with the chondrules. The second specimen shows the weathered fusion crust. The third specimen shows a partial fusion crust and a polished section just above the bottom that shows the metallic flakes. It is believed that this meteorite fall occurred around 10,000 years ago.
Gibeon slice
showing Widmanstatten Structure
It is classified as a fine octahedrite, Group IVA. The composition is roughly 90% iron, 8% nickel, 0.4% cobalt and 0.04% phosphorus. The mineral Kamacite makes up about 99% of the meteorite. Gibeon meteorites have also been found to have Troilite (which usually forms nodules), Chromite, Daubreelite, Enstatie and rarely, Tridymite.
Chinga
Meteorite. This is an end cut and the first image shows the natural
surface while the second image displays a polished surface.
The Chinga Meteorite is from the Chinga river bed in Tanna Tuva, Turvinskaya, Russia. It was first discovered in 1911. This meteorite is of a type known as ATAXITE and is considered rare. The Ataxites do not display Widmanstatten structure which in this case may be due to the high nickel content. The Chinga meteorites contain about 16% nickel. But as you can see, they do take a high, mirror-like polish.
These
are a couple of Canyon Diablo Meteorites from near Meteor Crater in Arizona.
The specimen on the left shows what the meteorite would look like if you were to
find it on the desert. It is encrusted with rust and a caliche like
coating. The specimen on the right has been wire brushed to remove the
weathered coating to reveal a more metallic looking specimen.
The Canyon Diablo Meteorite is classified as a coarse octahedrite, Group I.
Here is a link that will take you to an image of Meteor Crater.
Odessa Crater,
Texas - An Iron meteorite.
These are two pieces of the Brahin Pallasite that was discovered near Brahin,
Minsk, Belorussia in ~1810.
Another section
of the Brahin Pallasite.
Pueblito de
Allende, Chihuahua State, Mexico. The Allende meteorite is classified as a
CV3 carbonaceous chondrite.
Front
and back views of another Allende.
Close up view of the above meteorite showing chondrules.
Close up view of above meteorite showing detail of fusion crust.
A portion of the Gibeon meteorite that was found in 1836 in Namibia. It is
officially classified as a fine octahedrite type IVA. The meteorite was
cut with a diamond saw, polished and then etched in nitric acid to bring out the
Widmanstatten structure. The acid readily dissolves the Kamacite (an
iron-nickel mineral) portion leaving the crystal pattern in relief.
Seymchan
Meteorite from Russia. This is a iron / Pallasite. This meteorite
was found in 1967 near Seymchan in eastern Russia (Magadan district).
Initially it was classified as a coarse octahedrite, Iron IIE. During a
more recent expedition (2004?) more specimens were found but with a difference -
they contained olivine making it a Pallasite. This is a significant find
geologically speaking in that the association of coarsely crystalline iron mixed
with olivine could represent the boundary of core and mantle materials in a
large planetary body. (At least large enough for differentiation to take
place. Within the Earth the lower mantle gives way to the liquid iron outer
core.)
TEKTITES: Information to come soon.
