Plessite is a meteorite texture consisting of a fine-grained mixture of the minerals kamacite

Kamacite

Kamacite is a mineral. It is an alloy of iron and nickel, usually in the proportions of 90:10 to 95:5 although impurities such as cobalt or carbon may be present. On the surface of Earth, it occurs naturally only in meteorites. It has a metallic luster, is gray and has no clear cleavage although...

 and taenite

Taenite

Taenite is a mineral found naturally on Earth mostly in iron meteorites. It is an alloy of iron and nickel, with nickel proportions of 20% up to 65%.The name is derived from the Greek for "band". Taenite is a major constituent of iron meteorites...

 found in the octahedrite

Octahedrite

Octahedrites are a class of iron meteorites within the structural classification. They are the most common class of iron meteorites.They are composed primarily of the nickel-iron alloys: taenite - high nickel content, and kamacite - low nickel content....

 iron meteorite

Iron meteorite

Iron meteorites are meteorites that consist overwhelmingly of nickel-iron alloys. The metal taken from these meteorites is known as meteoric iron and was one of the earliest sources of usable iron available to humans.-Occurrence:...

s. It occurs in gaps between the larger bands of kamacite and taenite which form Widmanstätten patterns.

Many types of plessite exist and vary in formation mechanism and morphology. Some types of plessite as named by Buchwald's "Iron Meteorites" and Massalski's "Speculations about Plessite" are:

• acicular or type I plessite
• black or type II plessite
• cellular or type III plessite
• comb plessite
• net plessite
• pearlitic plessite
• spheroidized plessite