“Sphene twinned on (100) with unusual flat prismatic habit and remarkable pleochroism This crystal was understood after a brainstorming: Forms Involved in Titanite Crystal”

“Opposite side with white background that highlights needle inclusions Interfacial angle between frontal and shiny face is 34º (+/-1º)”

“Lateral view from one and other side Interfacial angle between faces in front edges is 113º (+/- 1º) in both cases Twinned or single crystal? elucidation in Forms Involved in Titanite Crystal ”

“Diagonal views from one side ...”

“... and from the other side”

“Above: View from the elongated axis (c-axis) Note that left side seems thicker because it's closer, faces up and down are parallel Below: Seen perpendicular to the upper edge Fracture or termination? ... the answer in: Forms Involved in Titanite Crystal”

“Pleochroic when backlit by the polarized light of a computer screen Same camera setting, no photoshopping”

“Crystal faces and twinning were understood after a brainstorming: Forms Involved in Titanite Crystal Crystal scheme drawn by Pete Richards”