Pectolite

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Larimar
Dominican Republic
6.75 carats

Pectolite is named after Greek "pektos" - well put together, alluding to its compact structure.

Pectolite usually occurs as translucent globular masses or crystals showing tabular habit. The material is colourless, white, bluish, greenish.

Massive pectolite from the Dominican Republic of light blue to sky-blue colour may be offered as a turquoise substitute under the trade name Larimar. Pectolite from Alaska has been used as a jade substitute.

Pectolite Gemstones by Colour

This table shows the variety of hues this gemstone can be found in. Click on a photo for more information.
 
 
 
 

Pectolite Gemstones by Size

This table shows distribution of Pectolite gemstone sizes that are listed on this site. This can give a good indication as to the general availability of this gemstone in different sizes.
Contributed photos
Lightest:2.01 cts
Heaviest:54.0 cts
Average:13.47 cts
Total photos:29
Do you have a larger Pectolite? Why not upload a photo?
2.01ct to 7.21ct7.21ct to 12.41ct12.41ct to 17.61ct17.61ct to 22.81ct22.81ct to 28.01ct28.01ct to 33.20ct33.20ct to 38.40ct38.40ct to 43.60ct43.60ct to 48.80ct48.80ct to 54.00ct
General Information
Varieties/Types:
Larimar - Blue variety of pectolite found in Dominican Republic
Chemical Formula
Ca
 
2
NaHSi
 
3
O
 
9
Ulrich Henn and Claudio C. Milisenda, Gemmological Tables (2004)
More from other references
Photos of natural/un-cut material from mindat.org
Pectolite Simulants
Sometimes used as jade simulant - Blue Chart Gem Identification, Herve Nicolas Lazzarelli, 2010, p 5
Physical Properties of Pectolite
Mohs Hardness4.5 to 5
Walter Schumann, Gemstones of the world (2001)
More from other references
Specific Gravity2.74 to 2.90
Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
More from other references
TenacityBrittle
Arthur Thomas, Gemstones (2009)
Cleavage QualityPerfect
Michael O’Donoghue, Gems, Sixth Edition (2006)
More from other references
FractureSplintery
Arthur Thomas, Gemstones (2009)
Optical Properties of Pectolite
Refractive Index1.595 to 1.645
Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
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Optical CharacterBiaxial/+
Ulrich Henn and Claudio C. Milisenda, Gemmological Tables (2004)
More from other references
Birefringence0.028 to 0.038
Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
More from other references
PleochroismNil
Arthur Thomas, Gemstones (2009)
DispersionVery weak
Arthur Thomas, Gemstones (2009)
Colour
Colour (General)Light blue, light green, colourless, gray.
Walter Schumann, Gemstones of the world (2001)
More from other references
Causes of ColourBlue, Cu2+ in octahedral coordination
W. William Hanneman, Pragmatic Spectroscopy For Gemologists (2011)
TransparencyTransparent,Translucent
Walter Schumann, Gemstones of the world (2001)
More from other references
LustreSilky
Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
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Fluorescence & other light emissions
Fluorescence (Short Wave UV)Yellow-orange common and phosphorescence
Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
Fluorescence (Long-Wave UV)May show orange-pink fluorescence under (material from Bergen Hill New York, USA) and a yellow fluorescence with green phosphorescence(Paterson, New Jersey, USA)
Michael O’Donoghue, Gems, Sixth Edition (2006)
Crystallography of Pectolite
Crystal SystemTriclinic
Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
More from other references
HabitGlobular masses, the rarer crystals showing tabular habit
Michael O’Donoghue, Gems, Sixth Edition (2006)
More from other references
Geological Environment
Where found:Occurs in nepheline syenites.
Michael O’Donoghue, Gems, Sixth Edition (2006)
Further Information
Mineral information:Pectolite information at mindat.org
Significant Gem Localities
Canada
 
  • Québec
    • Estrie
      • Les Sources RCM
        • Asbestos
Gems, Sixth Edition, Michael O’Donoghue, 2006, p. 435
    • Montérégie
      • La Vallée-du-Richelieu RCM
        • Mont Saint-Hilaire
Gems, Sixth Edition, Michael O’Donoghue, 2006, p. 435
Dominican Republic
 
  • Barahona Province
    • Sierra de Baoruco
      • Los Checheses
Gems, Sixth Edition, Michael O’Donoghue, 2006, p. 435
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