METEORITE OR METEORWRONG?ordinary chondritesMost (>95%) stony meteorites are ordinary
chondrites. Below are some photos of sawn faces of ordinary chondrites
in the Washington University collection. For most of the photos, clicking
on the image will bring an enlargement. The brightest materials in each
photo are metal grains (veins in "Richarton"). Ordinary chondrites
contain iron-nickel metal and, consequently, will
attract even a cheap magnet. |
![]() |
![]() |
||||||
Identified
as "Richarton, ILL." possibly Richardton
H5 (North Dakota, fall, 1918). In the closeup on the right, saw marks are visible in the metal vein. Notice that the metal grains are typically less than 1 millimeter in size. |
|||||||
![]() |
![]() |
||||||
![]() |
![]() |
||||||
Mocs
L6 (Romania, fall, 1882). In the closeup on the right, saw marks are visible
in the metal grains. |
|||||||
![]() |
![]() |
||||||
![]() |
![]() |
||||||
Two views
of a sawn slice of Independence
L6 (Missouri, fall, 1917), with electronic flash lighting (LEFT, with
millimeter ticks on scale) and natural sunlight (RIGHT). Click on image
for enlargement. Thanks to Karl Aston for the sample. |
|||||||
![]() |
![]() |
||||||
Two views
of a sawn slice of Cape
Girardeau H6 (Missouri, fall, 1846), with electronic flash lighting
from two different angles. Click on image for enlargement. Thanks to Karl
Aston for the sample. |
|||||||
![]() |
![]() |
||||||
Unnamed Northwest
Africa (NWA) H5 chondrite |
|||||||
![]() |
![]() |
||||||
An unnamed,
probably LL, chondrite from the US. Sawn face on left, exterior with fusion
crust on right. ![]() A large slice of a new stone of the L4 chondrite Seminole. There are thousands of sub-millimeter metal grains in this slice. (See "meteorwrong" number 273) |
|||||||
![]() |
|||||||
Sawn face of
Harper Dry Lake 036 (L6; find, 2010, CA). This meteorite shows dark veins
of impact melt, a feature sometimes seen in ordinary chondrites. All of
the small (<1 mm) light-colored specks in the image are metal grains.
Millimeter ticks for scale (bottom). Click on image for enlargement (big). |
|||||||
![]() Chondrules and metal grains on a sawn face of an unnamed chondrite (probably H5) from northern Chile. (See "meteorwrong" number 273). This photo was taken with natural light from a north-facing window on a sunny, clear day, so it looks a bit blue. Millimeter scale in background. |
|||||||
![]() Here's a sawn face of another unnamed (L?) chondrite showing metal grains and chondrules. (See "meteorwrong" number 293). This photo was taken with light from a high-intesity desk lamp. I rebalanced the color to make the gray background be gray. Millimeter scale in background. |
|||||||
![]() |
![]() |
||||||
Ordinary chondrite
pebbles found in the Sahara desert. Most are broken, but a partial fusion
crust is intact on many of them. Notice that despite that all of them
contain metal, they are not rusty colored. |
|||||||
![]() |
![]() |
||||||
|
![]() |
||||||
This meteorite violates a
number of the recognition principles that I stress in "A
Photo Gallery of Meteorwrongs." There is no obvious fusion
crust. The surface is not glassy or shiny; there are no regmaglypts.
The exterior has some ridges and one point. It's clearly a broken fragment
of a larger meteorite. If you look closely at the image on the upper left
(click on image to enlarge), however, there are shiny metal grains along
all the protuberances (points, ridges) because these areas have been abraded
from handling. Also, the specific gravity is 3.42,
well within the range of ordinary chondrites.
|
|||||||
![]() |