The Mineral PECTOLITE

Chemistry: NaCa2Si3O8(OH), Sodium Calcium Silicate Hydroxide
Class: Silicates
Subclass: Inosilicates
Group: Pyroxenoid
Uses: mineral specimens and as a semi-precious stone.
Specimens
Also see variety specimens:
Lorimar Specimens

Pectolite is a mineral that can be confused with several other similar appearing minerals. These include okenite, wollastonite, artinite and a few others. Fortunately, most of these minerals do not form with zeolites as pectolite is so apt to do. Okenite is one of those that does, but is soft and bendable, unlike pectolite.

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.

PHYSICAL CHARACTERISTICS:

Color is white, colorless or gray and also pale to sky blue in Lorimar.
Luster is vitreous to silky.
Transparency: Crystals are transparent to translucent.
Crystal System is triclinic; bar 1
Crystal Habits include fibrous tufts, radiating acicular crystal clusters and compact or botryoidal masses.
Cleavage is perfect in two direction at close to right angles.
Fracture is splintery due to the cleavage.
Hardness is 4.5 - 5
Specific Gravity is approximately 2.7 - 2.9 (average)
Streak is white.
Associated Minerals are various zeolites, prehnite, calcite, datolite and serpentine.
Other Characteristics: Splinters of pectolite do not bend and are brittle. They are also sharp and can easily puncture the skin if not handled properly. Also some specimens can be triboluminescent.
Notable Occurrences include Lake Co., California and Paterson and Franklin, New Jersey, USA; Bahamas, Dominican Republic; Italy and England.
Best Field Indicators are crystal habit, association with zeolites, brittleness and cleavage.