Acapulcoites

The name of this small group of primitive achondrites is derived from its only witnessed fall, the meteorite of Acapulco that fell in Mexico in 1976. Since its composition is nearly chondritic, Acapulco was initially classified as an anomalous chondrite, although it does not contain any relict chondrules. However, when similar meteorites were subsequently found, the acapulcoite group was formed to describe a distinct class of primitive achondrites. Acapulcoites mark the transition between primordial chondritic matter and more differentiated rocks. The acapulcoite group presently comprises 12 members, if one excludes probable pairings.

Acapulcoites are composed primarily of fine-grained olivine, orthopyroxene, minor plagioclase, nickel-iron metal, and the iron sulfide, troilite. They have mineral compositions that are intermediate between those of E and H chondrites, but they exhibit a characteristic oxygen isotopic pattern distinct from all other known chondrite groups. Importantly, some acapulcoites have been shown to contain a few relict chondrules such as the meteorite of Monument Draw, Texas, and one member actually exhibits an abundance of distinct chondrules - our recent find from Tissemoumine, Morocco, officially named NWA 725. This unique acapulcoite is actually a scientific sensation, and it is one of our best finds. The presence of distinct chondrules within NWA 725 attests to the fact that the acapulcoites represent an extremely primitive group, a true transition between chondrites and achondrites. It is thought that they originated on the same parent body as the closely related lodranites, another class of primitive achondrites.

Acapulco Witness Fall : 1976 August 11, 11hrs TKW 1914 gr Mexico, Guerrero Acapulcoite
				Acapulco 00 Type specimen for the acapulcoite group !!! endcut with nice crust and an open window SOLD          price on request
Acapulco 01 Type specimen for the acapulcoite group !!! nice slice 0.92gr       SOLD