Andalusite is a strikingly beautiful gem, but it is largely unknown to the general public and considered to be one of the lesser-known gem types in the trade. Andalusite gemstones are found in very distinct combinations of colors, and a very pronounced level of pleochroism, which results in the exhibition of different colors when viewed from different angles.Andalusite colors depend on the orientation of the crystal, but it typically occurs in yellow, yellow-green, green, brownish-red, olive and reddish-brown. Andalusite typically occurs translucent to opaque, with transparent gemstone-quality specimens being very rare.
Source: Wikipedia
