RUTILE
Specimen rut-17
$ 32.00Dims: 0.7 x 0.5 x 0.2" (1.8 x 1.3 x 0.5 cm)
Wt: 9.6 g w/ specimen box
Diamantina, Minas Gerais, Brazil
Two Rutile prisms make up this small thumbnail specimen. Though they are documented as a "Rutile Twin", I do not believe that they are, as what would be the twinning plane is uneven. One of the crystals is broken and mostly incomplete, but the other is in excellent condition and reaches a length of nearly 0.7" (1.8 cm). It has exceptional tetragonal form with a very good diamond-shaped cross-section, well-defined edges, and striated but clean faces. Its luster is adamantine and its color is such a dark red-brown that it appears to be nearly opaque. Only a few small internal fractures reflect enough light so that one can accurately determine its color. There is no host rock present, and the piece is affixed inside a plastic specimen box with a sticky wax.