Diaspore as a Gemstone and as a Source of Materials of interest in Different Fields

Diaspore is an aluminium oxide hydroxide, AlO(OH), and it is a relatively common mineral in metamorphic bauxite deposits. Its chemical and physical behaviour, in particular thermal treatment leading to corundum was investigated by several authors. Diaspore was once considered a collector’s gem, of which a variety called Turkish diaspore (trade name zultanite) displays a color-change phenomenon under different lighting conditions and is now used in jewelry. The aim of the present study is to revise previous experimental works in order to assess the dependence of the electronic, structural and mechanical properties on the conditions of the heating process.