Locality: Prospect Park quarry, northern New Jersey.
Name Origin: From the Greek pektos – “compacted” and lithos – “stone.”Pectolite is a white to gray mineral, NaCa2(HSi3O9), sodium calcium inosilicate hydroxide. It crystallizes in the triclinic system typically occurring in radiated or fibrous crystalline masses. It has a Mohs hardness of 4.5 to 5 and a specific gravity of 2.7 to 2.9. The gemstone variety, larimar, is a pale to sky blue.
Occurrence
It was first described in 1828 at Mt. Baldo, Trento Province, Italy and named from the Greek pektos – “compacted” and lithos – “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.
History
Discovery date : 1828
Town of Origin : MT. BALDO et MT. MONZONI
Country of Origin : ITALIE
Optical properties
Optical and misc. Properties: Transparent – Translucide – Luminescent, fluorescent – Gemme, pierre fine – Opaque – Macles possibles – Triboluminescent – Fragile, cassant – Tenace –
Refractive Index: from 1,59 to 1,64
Axial angle 2V: 50-63°
Physical properties
Hardness : from 4,50 to 5,00
Density: from 2,84 to 2,90
Color : colorless; white; grey white; whitish; grayish; grey; pink; green; red; yellowish
Luster : subvitreous; silky; nacreous
Streak: white
Break : conchoidal; irregular
Cleavage: Yes