# Sikhote-Alin meteorite

- Page: https://taslar.bumba.tr/en/stones/sikhote-alin-meteorite/
- Turkish: Sihote-Alin meteoriti
- Kind: Meteorite
- Classification: Meteorites and impact stones › Iron meteorites
- Hardness (Mohs): 4–5.5
- Specific gravity: 7–8 g/cm³
- Lustre: Metallic
- Transparency: Opaque
- Colours: blackish or bluish grey (fusion crust), rusty brown (shrapnel fragments), steel grey (cut surface)
- Composition: Iron–nickel alloy: about 93–94% iron, 5.5–6% nickel, about 0.4% cobalt and 0.46% phosphorus, with traces of sulfur, germanium and iridium. The main minerals are kamacite and taenite, with troilite, schreibersite and chromite.
- Texture: Massive metal; group IIAB, structural class “coarsest octahedrite”. The pieces are of two kinds: complete individuals with thumbprint-like hollows (regmaglypts) and fusion crust, and sharp-edged, torn metal fragments (shrapnel) broken apart in the air or on impact.
- Value ladder: 6/9 step, Fine ornamental and collector stone

A famous iron meteorite that fell in broad daylight in the Russian Far East in 1947, breaking up in the air and showering more than 23 tonnes of iron on the taiga.

The Sikhote-Alin meteorite is an iron meteorite that fell in the Sikhote-Alin Mountains of Primorsky Krai, Russia, on the morning of 12 February 1947. It was seen as a fireball brighter than the Sun, broke apart before reaching the ground and blasted more than a hundred craters and pits in the snowy forest. The recovered pieces add up to more than 23 tonnes, making it one of the largest iron meteorite showers ever seen to fall.

## How did it form?

Sikhote-Alin is an iron meteorite of group IIAB. Irons of this group are thought to come from the metal core of an asteroid that melted early in the Solar System's history: heavy iron and nickel sank to the centre, the core cooled very slowly over millions of years, and two iron–nickel alloys, **kamacite** and **taenite**, separated into interlocking crystals. Because Sikhote-Alin is poor in nickel, its kamacite bands are very wide, which places it in the class of “coarsest octahedrites”. Later collisions broke the piece away from its parent body and set it loose in space.

V. G. Fesenkov, chairman of the meteorite committee of the Soviet Academy of Sciences, worked out the object's orbit from eyewitness accounts. The orbit was an ellipse whose farthest point from the Sun lay in the asteroid belt, like those of many other small bodies that cross Earth's orbit.

## The fall: 12 February 1947

At around 10:30 a.m. local time, eyewitnesses saw a fireball brighter than the Sun coming out of the north. It came down at an angle of about 41 degrees at roughly 14 km per second and left a smoke trail about 32 km long. Its flash and roar were noticed up to 300 km from the impact site. Before entering the atmosphere it is estimated to have weighed 90–100 tonnes. It broke up at a height of about 5.6 km, and the pieces rained down on the snowy taiga forest. The largest crater was about 26 m across and 6 m deep, and some pieces were buried as deep as 6 metres.

In April 1947 a team of scientists and military engineers led by Fesenkov travelled to the site. In the years that followed, the Academy of Sciences gathered thousands of fragments; according to the sources, the iron that reached the ground and was recovered totals more than 23 tonnes.

## What is it used for?

Sikhote-Alin has no everyday use; its importance is scientific and historical:

- **A witnessed fall:** a shower of iron meteorites of this size that was both seen to fall and recovered is almost unique in recorded history. The eyewitness accounts allowed the orbit to be calculated and the break-up to be studied.
- **Craters and fragmentation:** the crater field is one of the rare examples showing how a metal body that breaks up in the air reaches the ground and what kind of pits it digs.
- **Museums and collections:** large pieces are held in the collections of the Russian Academy of Sciences and in Moscow museums, and small pieces are found in many museums and private collections around the world; a piece is also on display at Meteor Crater in Arizona, USA.

## Individuals and shrapnel

The recovered pieces fall into two groups. **Individuals** passed through the atmosphere on their own: they have regmaglypts resembling thumbprints and a thin fusion crust. **Shrapnel fragments** are sharp-edged pieces of metal torn apart by explosions in the air or on hitting the ground. Both kinds are found in museums and collections.

## How to recognise it

- Complete pieces show shallow thumbprint-like hollows (regmaglypts) and a thin, dark fusion crust; some carry flow lines left by melted metal.
- The pieces called shrapnel look like bent and torn metal with sharp edges and are usually rusty brown; they formed when the meteoroid broke apart in the air and on impact.
- Being almost pure iron–nickel, it is far heavier than a rock of the same size and strongly attracts a magnet; its nickel content is about 6%.
- Only documentation, and if necessary a laboratory analysis, can show that a piece really comes from Sikhote-Alin; the meteorite's official record is in the Meteoritical Society's database.

## Fakes and imitations

- Scrap iron and steel: rusty, sharp-edged industrial iron can look like shrapnel, but it contains no nickel and may show cutting, casting or welding marks.
- Slag: may attract a magnet, but it is full of gas bubble holes and is not metal.

## What determines its value?

Because more than 23 tonnes of Sikhote-Alin were recovered, small specimens are relatively easy to find on the collector market; the shape and condition of a piece matter more than rarity. Complete individuals with clear regmaglypts, preserved fusion crust and flow lines, and an oriented shape are more sought after than shrapnel fragments. Specimens without advanced or scrubbed-off rust, and with clear documentation and provenance, are preferred.

This information is educational, not buying, selling or investment advice. Value varies enormously with quality and treatment.

## Myths and misconceptions

- Myth: Sharp-edged, torn-looking pieces of iron cannot be meteorites; they must be war shrapnel or scrap. Fact: Part of the Sikhote-Alin material looks exactly like that: as the meteoroid broke up in the air and hit the ground, the metal was torn into sharp-edged “shrapnel”. The reverse does not hold either, though; not every piece that looks like this is a meteorite, and a nickel analysis and documentation are needed.
- Myth: Every meteorite fragment is extremely rare and priceless. Fact: Some meteorites really are very rare, but more than 23 tonnes of Sikhote-Alin were collected and its small pieces are widely available on the collector market. A meteorite's value depends on its type, the story of its fall, its size and its condition.

## Did you know?

- The Soviet artist P. I. Medvedev was sitting at his window starting a sketch when the fireball appeared, and he immediately drew what he saw. On 20 November 1957, the tenth anniversary of the fall, the Soviet Union issued a stamp showing his painting.
- The village of Beitsukhe near the crater field was renamed Meteoritny (“Meteoritic”) in 1972.
- One of the largest pieces weighs 1,745 kg and is on display at the Fersman Mineralogical Museum in Moscow.

## Where is it found?

- Sikhote-Alin Mountains, Primorsky Krai, Russia (Type locality): The crater field where it fell on the morning of 12 February 1947, near the village formerly called Beitsukhe, renamed Meteoritny in 1972. The largest crater was about 26 m across and 6 m deep.

## Sources

- [Sikhote-Alin meteorite](https://en.wikipedia.org/wiki/Sikhote-Alin_meteorite), Wikipedia
- [Сихотэ-Алинский метеорит (Sikhote-Alin meteorite)](https://ru.wikipedia.org/wiki/%D0%A1%D0%B8%D1%85%D0%BE%D1%82%D1%8D-%D0%90%D0%BB%D0%B8%D0%BD%D1%81%D0%BA%D0%B8%D0%B9_%D0%BC%D0%B5%D1%82%D0%B5%D0%BE%D1%80%D0%B8%D1%82), Wikipedia (Russian)
- [Sikhote-Alin](https://monnigmuseum.tcu.edu/meteorites/sikhote-alin/), Monnig Meteorite Gallery, Texas Christian University
- [Sihote-Alin](https://tr.wikipedia.org/wiki/Sihote-Alin), Vikipedi
- [Kamacite Mineral Data](http://webmineral.com/data/Kamacite.shtml), Webmineral.com
- [Taenite Mineral Data](http://webmineral.com/data/Taenite.shtml), Webmineral.com
- [Density and specific gravity (R. L. Korotev)](https://sites.wustl.edu/meteoritesite/items/density-specific-gravity), Washington University in St. Louis, Some Meteorite Information
- [Iron meteorites](https://meteorites.asu.edu/meteorites/iron-meteorites), Buseck Center for Meteorite Studies, Arizona State University


Source: https://taslar.bumba.tr/en/stones/sikhote-alin-meteorite/ · Licence: CC BY-SA 4.0