Indium arsenide - InAs
Indium arsenide is a semiconductor, used in electronic devices. This material has a remarkably light color. It is purely grey, and when broken, the material has metallic lustre, albeit somewhat darker than real metals (it is more like silicon). The larger piece also shows that this material consists of crystals of different orientation. The vague color differences show this polycrystalline nature of this material. The largest piece has a longest diameter of well over 1 cm.
The material can be polished, such that it becomes smooth like a mirror. The piece at the top of the picture has a polished rim, and the other piece is reflected in this rim. It is smooth like a mirror, but the mirror image is darker than the object itself. This is due to the grey color of the compound.