The Pallas Iron (Krasnojarsk)

This is one of the most famous meteorites in the world, and the first pallasite found, which created the Pallasite group, named after Peter Simon Pallas.

Here's part of the main mass:

Figure 1.

Here's the story

It was 1749, on the side of Mount Bolshoi Imir, about 120 miles southeast of Krasnojarsk, Russia.

Figure 2.

Mountains around Krasnojarsk, Siberia.

Yakov Medvedev was searching for ore veins and found a mysterious iron boulder lying in the open air with no sign of an impact crater.

Figure 3.

Location of Krasnojarsk within Siberia, Russia.

Over two decades (22 yrs) after Medvedev's find, a German copper miner named Johann Kaspar Mettich, wrote a report to Peter Simon Pallas, saying he saw an iron boulder lying in the open, discovered by a Cossack named Medvedev in 1749. He added that the iron was used by the locals as a "raw iron" source.

Figure 4.

Peter Simon Pallas

Peter Simon Pallas (1741-1811), a renowned scientist, academician, naturalist, and traveler examined the mass. The local tribes told him that the huge iron boulder had fallen from the Heavens.

What startled Palas was that the iron, partly covered with a black crust and many translucent olivine crystals, had never been written or talked about. It was completely unknown and unique.

Pallas described the find as an iron mass 'having cavities filled with small olivine crystals.' Recognizing its importance, Pallas registered the iron mass and organized its transportation to St. Petersburg.

Some decades later analysis of the metal showed that it was a new type of meteorite: a stony-iron, a group later called "Pallasites" after Pallas. However, today the meteorite is named Krasnojarsk, Although, many also call it the “Pallas Iron.”

Figure 5. Ernst Florens Chladni.

In 1794, encouraged by Pallas, Ernst Florens Chladni, a German physicist, known as the father of meteoritics – the study of meteorites – analyzed the unusual iron and began to convince skeptics that meteorites did indeed originate far from Earth.

Later, the Krasnojarsk pallasite also became the first meteorite to be etched with acid (by G. Thomson) and therefore was the first one to show to human eyes the Widmanstätten pattern.

Here's a photo of a section of the meteorite, from our education collection:

Figure 6. Krasnojarsk, 23.5 grams. Unetched.

Just The Specs

Pallasite - essentially olivine and pyroxene and metals

Olivine (66%)
Iron (23.5%)
Nickel (8.5%)
Schreibersite (0.76%)
Troilite (0.46%)
Chromite (0.31%)

Total iron accounts for 19.22% of its volume.

Found 1749

Krasnojarsk, Russia

Terms

As with other meteorites, the composition of Krasnojarsk teaches us about minerals and structure.

Definition of Chromite

n. A black submetallic mineral consisting of oxide of chromium and iron – also called chromic iron.

Photo from http://www.neab.net/oldgeo/locality/finland/horsmana.htm

Definition of Olivine

Noun. A yellowish green mineral consisting of magnesium iron silicate; a source of magnesium.

Here's an example:

Photo from NASA Ames Research Center, Tom Trower.

Definition of Schreibersite

n. A mineral occurring in steel-gray flexible folia (thin layers). It contains iron, nickel, and phosphorus, and is found only in meteoritic iron.

This cut surface shows numerous troilite (see below) and also schreibersite inclusions. Often the different structures are separated by elongated schreibersite worms.

Photo from http://www.meteorite-recon.com/en/meteorite_santa%20fe.htm

Definition of Troilite

n. Native iron protosulphide, FeS. It is known only in meteorites, and is usually in embedded nodular masses of a bronze color.

Here's a picture of a troilite inclusion:

Photo from http://www.lexic.us

Links

Here's a link to the American Museum of Natural History, discussing pallasite formation and giving three theories to why no meteorites have been found from an asteroid's olivine mantle?

http://www.amnh.org/exhibitions/permanent/meteorites/planets/mantle.php

Here's A Brief History of Meteoritics

http://www.meteoris.de/basics/history1.html

http://imca.repetti.net/metinfo/index.html

Here's two dictionaries for reference:

http://www.science-dictionary.org/

Lexic also includes excellent pictures:

http://www.lexic.us/

Here's a link to the New England Meteoritical Services. Contact Russell Kempton, Director, and explain what you need:

http://www.meteorlab.com

Figures & Acknowledgments

Figures

Figure 1. Photo from http://www.nhm.ac.uk/nature-online/virtual-wonders/vrmeteorite.html

Figure 2. Photo from http://www.mountain.ru/eng/photo/02-2000/archive_photo02.shtml

Figure 3. http://commons.wikimedia.org/wiki/File:Location_Krasnoyarsk_Map_of_Russian_subjects,_2008-03-01.png

Figure 4. Photo from http://www.volgagermans.net/norka/early_years.html

Figure 5. Photo from http://www.meteoris.de/basics/history1.html

Figure 6. Photo by New England Meteoritical Services. www.meteorlab.com