Martin Horejsi

 
An Article In Meteorite Times Magazine
Martin Horejsi's Meteorite and Tektite Books


 

An April 1891 Witnessed Fall: Indarch, Azerbaijan

History, Chondrules, Metal, Oh My!

But what the *#&$%@ happened to it?


Indarch EH4 meteorite

 

Shortly after eight o’clock in the evening on April 7th of 1891, a meteorite inducing ball of fire flew across the sky above Azerbaijan as numerous people watched and listened to the sonic booms. The next morning, a single 27kg stone was found.

The high iron content of the Indarch meteorite along with its excellent chondrule character and definition led to the classification of this stone as an EH4 Enstatite Chondrite with an S2 shock stage.

 

Indarch EH4 meteorite

 

Unfortunately, this sliced fragment of Indarch looks like it got hit with the ugly stick, then went back for seconds.

It has four cut faces and almost twice that in broken ones, not to mention the chips cuts, and other wounds and avulsions peppering its poor body.

I suspect that this piece is what was left over after scientists thoughtlessly lopped off what they wanted.

 

In the Journals

Indarch is the subject of many scientific papers including the following available online:

A Model for the Formation of E Chondrites

Indarch SiC by TIMS, RIMS, and NanoSIMS

Evolution of Indarch (EH4 chondrite) at 1 GPa and high temperature

MN-CR Systematics in Sulfides of Unequilibrated Enstatite Chondrites

Difficult Experiments on Weird Rocks: Can you turn an E chondrite into an enstatite achondrite?

Rudashevskyite, the Fe-dominant analogue of sphalerite, a new mineral: Description and crystal structure

 

Indarch EH4 meteorite

 

The blocky form of my collection piece makes it look smaller than its 19 grams. Just another unfortunate aspect to this historic and valuable specimen.

As I was working on this article, I did my usual Google surfing for images. Surprisingly there are very few pictures of Indarch on the web. And most of those pieces that are pictured in cyberspace are a gram or smaller in mass. I found this odd given 27kg starting weight, the distribution if Indarch in collections worldwide, and the hefty weight of published papers citing Indarch.

In fact, when adding up all the weights of the distributed specimens listed in the Catalogue of Meteorites, over 18kg is accounted for in collections around the globe.

I wonder if all the pieces of Indarch used in research were bludgeoned off the piece I now hold.


 

Are E Chondrites from Mercury?

After our minds opened to the fact that some of the meteorites in our collections are from nearby bodies including Mars, it didn't take long to for us to plant an eye of suspicion on the tiny planet of Mercury. Because of the iron-rich, oxygen-poor makeup of E chondrites including Indarch, Mercury looked like a good parent body candidate compared to the other options out there.

However, later inspection of the E and M-Type asteroids appear, in reflectance spectra anyway, to more closely match the composition of the E chondrites than Mercury. But for some folks the jury is still out which is why the question of whether or not an E chondrite can be turned into an E achondrite is an important one.

 

Indarch EH4 meteorite

 

Although the battered surface of this specimen more closely matches its natural state in space than a cut and polished face, it is small consolation for such a lousy job of preparing this specimen.

Good grief you people who worked on it. What were you thinking?


Indarch EH4 meteorite

 

Is that a patch of crust? Not with my luck.

Three strikingly different textures are visible here. The cut face and the broken face are easy to identify, but the other smoothish but more natural looking surface may or may not be crust.

last week, I received a land use survey recently for the open space surrounding the community I live in. It became clear when reading between the questions that the survey writers foresight was limited to five years. That just a heartbeat in the big picture. Now apply that to meteorites.

Indarch fell almost 120 years ago, and I doubt that any of those who sliced or broke off pieces off this particular specimen ever dreamed that it would be the showpiece of an online article that any of the 1,596,270,108 internet users in the world can view. So for current owners and curators of meteorites, heed the words of Aretha Franklin and R-E-S-P-E-C-T the specimens for you never know what the future holds for them.


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