Pectolite

Pectolite is a white to gray mineral. It crystallizes in the triclinic system typically occuring in radiated or fibrous crystalline masses. It has a Mohs hardness of 4.5 to 5 and a specific gravity of 2.7 and 2.9. The gemstone variety, larimar is a pale to sky blue.

Occurrence
In 1828, Pectolite was first described at Mt. Baldo, Trento Province, Italy and named from the Greek pektos meaning "compacted" and lithos meaning "stone".

It occurs as a primary mineral in nepheline syenites, within hydrothermal cavities in basalts and diabase and in serpentinites in association with zeolites, datolite, prehnite, calcite and serpentine. It is found in a wide variety of worldwide locations.

Pectolite is a nice specimen type mineral, meaning that it can form interesting specimens from time to time. However it was not all that well-regarded until a variety was discovered in the Bahamas and the Dominican Republic. It has been given the trade name Larimar and has enjoyed success in the semi-precious stone market.

Source

 * http://en.wikipedia.org
 * Amethyst Galleries