Juvinas (eucrite) – 1.65g

$ 355.00

1 in stock

Description

1.65g with crust

Sold with label/certificate of authenticity


Eucrite, monomict
Fall – 15 Jun 1821, 91 kg

The Juvinas meteorite fell with loud detonations in 1821 and was only the third of 34 witnessed eucrite falls. However, only the 330 kg Millbillillie fall of 1960 has since surpassed it in mass. Approximately 40 kg of Juvinas has been curated in France so samples are still made available for various mineralogical, geochemical, and isotopic studies. Apparently a product of near surface volcanism on an ancient asteroidal homeworld (presumably Vesta), the components of Juvinas have apparently taken a substantial beating from impacts. However, the meteorite is relatively homogeneous (‘monomict’) and does not exhibit the extraordinary mineralogical variety found in other meteorites with similar ~4.56 billion years old ages. The meteorite lithology is dominated by pigeonite accompanied by plagioclase. Most of the pigeonite contains exsolved augite typical of many near surface lavas that cool much more quickly than plutonic rocks. Silica polymorphs are found as small inclusions in some pyroxene and plagioclase grains (both quartz and tridymite have been identified). Minor amounts of chromite, ilmenite, and zircon have been identified as well. The zircon is particularly helpful in attempting to ascertain a reliable chronology. Small phosphates also contribute to this effort. Most studies seem to indicate that the dominant mineralogical constituents were formed near the surface of an asteroid well over 4.5 billion years ago, remained somewhat near the surface for a few hundred million years or so, and at some time a moderately large object was ejected into space by a strong impact. A relatively recent impact some 10-12 million years ago dislodged a small meteoroid. This now small meteoroid, unprotected by any substantial overburden, was then exposed to cosmic rays before it struck the earth nearly two centuries ago.