𝐓𝐚𝐧𝐞𝐳𝐫𝐨𝐮𝐟𝐭 𝟎𝟗𝟏. Mesosiderite. Slice (2.2 g)

Contains similar parts of metal and rock. It is a chaotic mix of the two materials, with some parts being a metallic matrix with rocky inclusions and others vice versa. With an orbit between Mars and Jupiter, the asteroid 16 Psyche is the main candidate as the parent body of the mesosiderites.

History: Two stones totaling 4988 g were found near Adrar, Algeria. Carlos Muñecas Muñoz purchased the samples from a dealer in Morocco in 2020.

Physical characteristics: Samples are dark brown in color, rounded, and lack fusion crust. Rounded metal nodules protrude through the surface. A cut face shows the interior is composed of a breccia containing: metal grains, cm-sized rounded metal nodules and silicate clasts (up to 4 cm) and mineral grains (up to 0.5 cm).

Petrography: Description and Classification (A. Love, App): Sample is a breccia composed of (vol%): cm-sized rounded metal nodules (3); cm-sized rounded lithic clasts (10) with cumulate and brecciated textures, mineral clasts set within a matrix of poikiloblastic orthopyroxene plagioclase and silicates and metal (~35vol%). Modal percentages (vol%) of silicates (image thresholding of 20 backscattered electron images): orthopyroxene (60), plagioclase (31), olivine (5) and a lath-shaped silica polymorph (4). Matrix pyroxenes are inverted and show blebby and lamellar exsolution. Olivine shows well-developed reaction coronas some of which have replaced entire grains. Grain boundaries between silicates are sutured. Additional minerals are: kamacite, taenite, lath-shaped Si polymorph, apatite, troilite, chromite, trace ilmenite.