The Johnstown meteorite comes from a large asteroid, probably Vesta, that melted and differentiated. It is low in iron, nickel and other elements that sank to the asteroid core. It is also poor in aluminum and calcium, which seeped to the surface in volcanic basalts like the Camel Donga meteorite in this case.
This sample is the "main mass" of the Johnstown meteorite, meaning it is the biggest fragment of Johnstown ever found.
Fell February 6, 1924 Weld County , Colorado, USA
Topic: Earth Science
Keywords: Asteroids, Astrogeology, Astrophysics, Chemical elements, Meteorites