Moonstone

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Moonstone is a variety of feldspar that displays an amazing optical phenomenon called, adularescence. Internallyrepeating feldspar layers scatter the light that enters the stone creating a mystical glow reminiscent of moonbeams.This glow comes to life, rolling across the gems surface, when it is moved. Adularescent labradorite with a multi-colored glow is sometimes called Rainbow Moonstone.

Moonstone Polished
Moonstone Classification
Common Name Moonstone
Species Feldspar
Moonstone Optical Properties
Transparency Transparent - Translucent
Refractive Index 1.518-1.568
Birefringence 0.005-0.011
Optic Character Biaxial
Optic Sign Positive or Negative
Polariscope Reaction Doubly Refractive (DR)
Fluorescence SWUV: inert to weak pink to red or orange, weak pinkish orange
LWUV: inert to weak yellowish white, blue, moderate chalky blue, pink or red
Pleochroism Unobservable
Moonstone Characteristic Physical Properties
Hardness 6-6.5
Streak White
Specific Gravity 2.520-2.750 Range:+/-0.05 Typical:2.690
Toughness Poor
Inclusions Moonstone occasionally contains colorless inclusions and might show parallel multiple twinning planes.
Luster Vitreous
Fracture Uneven, Splintery
Cleavage Perfect, in two directions
Moonstone Chemistry & Crystallography
Chemical Name calcium, sodium aluminum silicate
Chemical Formula NaAlSi3O8 and CaAl2Si2O8
Crystal System NA
Chemistry Classification Silicate

Moonstone Colors

  • White Moonstone White
  • Red Moonstone Red
  • Gray Moonstone Gray
  • Pink Moonstone Pink
  • Orange Moonstone Orange
  • Brown Moonstone Brown
  • Black Moonstone Black
  • Brown Moonstone Brown
  • Multi-color Moonstone Multi-color
  • Yellow Moonstone Yellow

Alternate Names

Rainbow Moonstone, Star Moonstone

Countries of Origin

Tanzania, United Republic Of; Myanmar; United States of America (the); Sri Lanka; Madagascar; Switzerland; French Polynesia; India; Mozambique; Unknown; Malawi; China; Russian Federation (the); Brazil

Care

Normal care

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Species/Variety

Blue Moonstone

Blue moonstone is the finest variety of labradorite moonstone. It is highly transparent and displays strong blue adularescence. The best specimens originally came from Myanmar (formally known as Burma), but it can also come from India, Madagascar, Malawi, Sri Lanka and Tanzania.

Blue Moonstone Moonstone
Blue Moonstone Classification
Common Name Blue Moonstone
Blue Moonstone Optical Properties
Birefringence 0.009
Blue Moonstone Characteristic Physical properties
Specific Gravity 2.650
Toughness Poor
Inclusions Moonstone occasionally contains colorless inclusions and might show parallel multiple twinning planes.
Stability Good

Moonstone-Labradorite

Labradorite moonstone is a variety of feldspar that displays an amazing optical phenomenon called adularescence. Labradorite is a plagioclase feldspar and a member of the triclinic crystal system. Internally repeating feldspar layers scatter the light that enters the stone creating a mystical glow reminiscent of moonbeams. This glow comes to life, rolling across the gems surface, when it is moved. Labradorite moonstone comes in colorless, white, slight orange or green with a blue sheen. Adularescent labradorite with a multi-colored glow is sometimes called Rainbow Moonstone.

Moonstone-Labradorite Moonstone
Moonstone-Labradorite Classification
Common Name Moonstone-Labradorite
Moonstone-Labradorite Optical Properties
Birefringence 0.009
Moonstone-Labradorite Characteristic Physical properties
Specific Gravity 2.650
Toughness Poor
Inclusions Moonstone occasionally contains colorless inclusions and might show parallel multiple twinning planes.
Stability Good

Moonstone-Orthoclase

Orthoclase moonstone is a variety of feldspar that displays an amazing optical phenomenon called adularescence. Orthoclase feldspar is a member of the monoclinic crystal system. Internally repeating feldspar layers scatter the light that enters the stone creating a mystical white glow reminiscent of moonbeams. This glow comes to life, rolling across the gems surface, when it is moved. It can be colorless to white, orange, yellow or brown.

Moonstone-Orthoclase Moonstone
Moonstone-Orthoclase Classification
Common Name Moonstone-Orthoclase
Moonstone-Orthoclase Optical Properties
Refractive Index 1.518-1.526 Tolerance:(+0.010/-0.010)
Pleochroism Typically none
Moonstone-Orthoclase Characteristic Physical properties
Specific Gravity 2.550
Toughness Poor
Inclusions Moonstone will have blue or white adularescence. Stones might have centipede like inclusions and material with aventuresence or asterism might contain reflective inclusions such as fine needles or elongated hematite platelets.
Stability Good

Rainbow Moonstone

Adularescent labradorite with a multi-colored glow is sometimes called rainbow moonstone. Rainbow moonstone is colorless and highly transparent and it displays an amazing optical phenomenon called adularescence. Labradorite is a plagioclase feldspar and a member of the triclinic crystal system. Internally repeating feldspar layers scatter the light that enters the stone creating a mystical glow reminiscent of moonbeams. This glow comes to life, rolling across the gems surface, when it is moved.

Rainbow Moonstone Moonstone
Rainbow Moonstone Classification
Common Name Rainbow Moonstone
Rainbow Moonstone Optical Properties
Birefringence 0.009
Rainbow Moonstone Characteristic Physical properties
Specific Gravity 2.650
Toughness Poor
Inclusions Moonstone occasionally contains colorless inclusions and might show parallel multiple twinning planes.
Stability Good

Adularia

Adularia is a variety of feldspar found in hydrothermal veins in mountainous areas, from one of which it derives its name: the Adular Mountains of Switzerland. It commonly forms colorless to white, cream, pale yellow to pink, or reddish-brown, glassy, prismatic, twinned crystals. These transparent to colorless gems often display a white to blue sheen.

Adularia Moonstone
Adularia Classification
Common Name Adularia
Adularia Characteristic Physical properties
Specific Gravity 2.520
Toughness Poor
Inclusions Adularia will display white or blue adularescence. Stones might have centipede like inclusions and material with aventuresence or asterism might contain reflective inclusions such as fine needles or elongated hematite platelets.
Stability Good
Tim Matthews

Author

Tim Matthews

Tim Matthews is President and Chief Executive Officer of Jewelry Television® (JTV), as well as a member of the company's Board of Directors. He oversees and leads all aspects of the company's powerful omni-digital retail platform that uniquely specializes in fine jewelry and gemstones. His passion for business and gemstones has led him to become a recognized expert in the field of gemology. He is a life member of the Gemmological Association of Great Britain (Gem-A) and has earned Gem-A's highest degrees, the Gemmology (FGA) and Diamond (DGA) diplomas. He is also a Graduate Gemologist (GG) of the Gemological Institute of America (GIA) and has also completed GIA's Graduate Diplomas in Diamonds, Colored Stones and Pearls. Under his leadership, JTV has become the leader in the sourcing and selling of color gemstones and jewelry.

This page was created on June 27, 2014.

This page was last edited on October 24, 2019.