From Mindat.Org Photo Of The Day; September 26, 2018:
Vesuvianite: (Ca,Na,☐)19(Al,Mg,Fe3+)13(☐,B,Al,Fe3+)5(Si2O7)4(SiO4)10(OH,F,O)10
Locality: Campagnano di Roma, Rome Province, Latium, Italy
“On a matrix consisting of pyroxene "fassaite", green in color, we can see in the upper right hand corner of the picture a perfect, small, light brown crystal of vesuvianite, with equal development of faces, while at the center of the picture a crystal with distorted faces for a different development of the same. The right side of the crystal in the center of the photo presents a face similar to a "Y ", that looks like the face of the trapezohedron (also called icositetrahedron) and, then, it might suggest a garnet (cubic system). Indeed, it is the dithetragonal bipyramid face, here similar to a "V" (probably the {211}), from whose low vertex begins the face of the second order prism {100}. Collection and photo by Gianfranco Ciccolini. Nikon D750, bellows, Luminar 25 mm.”