|Andalusite is an aluminum silicate closely related to both sillimanite and kyanite. All three minerals are polymorphs. They share the same chemical composition, but possess different crystal structures. Andalusite is a strikingly beautiful gem, but it is one of the lesser-known gem types in the trade.|
|Andalusite gemstones are found in very distinct combinations of colors, with a very pronounced level of pleochroism. |
New-found appreciation for andalusite is greatly owed to its unmistakable and unique twist on play of color. For many years andalusite has primarily been a collector's stone, but it has recently gained attention from jewelry designers.
It is an ideal hardness, about 7.5 on the Mohs scale.