MINERALOGY, PETROGRAPHY AND GEOCHEMISTRY OF CAVEZZO, A “DOUBLE-FACED” CHONDRITE

he Cavezzo meteorite, which fell on January 1st 2020, is the first meteorite detected and recovered by the Ital- ian PRISMA Fireball Network [1,2]. Two specimens, weighing 3.12 g (Cavezzo 1) and 52.19 g (Cavezzo 2), were collected three days after the bolide was observed. In the following days, the -ray activity was measured on Cavez- zo 2 at the INAF Monte dei Cappuccini Laboratory in Torino [3] showing the presence of many cosmogenic radioi- sotopes including 48V, typical of a recent fall.The type specimen, represented by the whole Cavezzo 1 and a chip from Cavez- zo 2, is on deposit at the Natural History Museum of the University of Firenze ((Inv. #s I3557 and I3613). The main mass (Cavezzo 2) is on deposit at the Museum of Planetary Sciences in Prato. Cavezzo 1 (lithology A) shows a very peculiar modal miner- alogy such as the relatively high amount of olivine (67 vol%), plagioclase (14.8 vol%), high-Ca pyroxene (9.1 vol%) and chlorapatite (3.1 vol%), low content of low-Ca pyroxene (5.6 vol%), metal (<0.1 vol%) and troilite (< 0.1 vol%) although the compositional values for olivine (Fa 24.24 mol%) and low-Ca pyroxene (Fs 20.41 mol%) are similar to those of the L chondrite group [4]. Cavezzo 2 specimen (main mass – lithology B) has a more typical L ordinary chondrite crystal chemistry and modal mineralogy. As concerns the values of oxygen isotopes, specimen 1 stands at the border between the lower values of the L group and the higher values of the H group (17O‰ 3.250; 18O‰ 4.736; 17O‰ 0.788) whereas specimen 2 is at the opposite border of the field (17O‰ 3.737; 18O‰ 4.957; 17O‰ 1.159). Even the bulk chemistry confirms a different content of many minor and trace elements (including REE) between the two lithologies.