Iron-Nickel Meteorite

Iron-nickel meteorite from Russia, 1 cm long

Iron-nickel appears rare on earth and most of it is extraterrestrial origin in form of meteorites.
Hundreds of meteorites fall on earth every day but most of them burn and do not survive the atmosphere reentry.
Meteorites contains a crust usually, formed from molten iron in the reentry and solidify when they cool down.
Most of them are found late after the impact and thus they rust with an orange iron-like rust.
Crystals are uncommon but some can show on polished faces.
In a humidified  area, iron-nickel meteorites will form a coated rust.

Meteorites fall in three categories: stony, iron and stony iron. all types have fusion crust, a burned layer formed on the reentry.
Stony meteorites are called ordinary Chondrites and make up about 80-90% of all falls and will be attracted to a magnet because it contains iron. A cu cross it will show tiny flecks of iron-nickel sprinkled throughout the extraterrestrial matrix comprised mostly of chondrules.
Some very rare meteorites have no iron-nickel like lunar and martian meteorites, they are rare and look like common earth rocks.
Iron meteorites are made up to 95% iron and nickel. This type is considered rare.
Stony iron meteorites are composed typically about 50% iron-nickel and 50% stony material. These includes both mesosiderites and pallasites. Pallasite is the most aesthetically pleasing. When pallasite are cut cross they are very beautifull.

Chemical formula: Fe; Ni; (Fe, Ni)
Color: steel-gray to black
Streak: steel-gray, shiny
Hardness: 4-5 Mohs
Crystal system isometric, tetragonal
Transparent opaque
Luster metallic
Specific gravity 7,9-8,9
Cleavage none
Tenacity: malleable and ductile
Special characteristics: ferromagnetic, very good conductor of electricity

Tests for steel-nickel meteorites:
Hardness 4-5; Streak steel-gray shiny; heavy
Strong attraction to magnets and very good electricity conductor
Rusts quickly in water or moisture
Surface features: cracks, crusts, contraction cracks but not necessary
They may be rusted on the surface if they fall a lot time ago
Fusion crust is a layer of burned material on a meteorite
No holes, no sharp edges, smooth features, surface slightly rough
The inside of a meteorite may look as full iron-nickel smooth or rock and alot of points matrix with metal look, flakes of metal