Sodalite's Rare Gemstone Uses

by

Kevin Faurot

www.emporia.edu/earthsci/amber/go340/students/faurot

Introduction

Sodalite is a rarely used mineral for making into a gemstone, but that doesn't mean it isn't used at all. Its low hardness makes it an undesireable gemstone because it is may be easily scratched. However, its beautiful color and exquisite designs found within leave some of us in awe. The most important thing to remember about gemstones is that beauty is in the eye of the beholder!

This site was created for a gemstone course from Emporia State University. The page covers basic properties of sodalite including (a)use, (b) where sodalite can be found, (c) what sodalite may be confused with, and (d) various facts about sodalite as a mineral and gemstone.

Table of Contents

Properties of Sodalite
Uses of Sodalite
Sodalite: Ornamental and Jewelry
Look Alikes
Origin of Sodalite
Related Links

Polished pointed sodalite specimens.


Image taken from: www.bestcrystals.com/sodalite.html.

Properties of Sodalite

Color: White, blue, gray
Transparency: Transparent to opaque
Streak Color: White
Refractive Index: 1.48
Hardness: 5.5-6.0
Double Refraction: None
Density: 2.14-2.40
Dispersion: 0.018 (0.009)
Cleavage: Indistinct
Pleochroism: Absent
Fracture: Uneven, conchoidal
Absorption Spectrum: Not diagnostic
Crystal System: (Cubic) rhombic dodecahedra
Fluorescence: Strong; orange
Chemical Composition: Na8Al6Si6O24Cl2

Table information obtained from Schumann (1997)

Uses of Sodalite

Sodalite is often used for jewelry but not in the type of jewelry you would find in your typical jewelry store. Sodalite is one of the few opaque blue colored gemstones. Frequently, sodalite has a mixture of colors including black and white veins streaking throughout and give it the unique look. White veins are calcite deposits. The deep blue and black, mixed with the white streaks remind me of a violent thunderstorm with lightning. Maybe this is nature's way of capturing such a beautiful thing in a stone that lasts a lot longer.

Sodalite is used for carvings which leaves an unlimited possibilities when it comes to variety of shapes and styles. Sodalite found as an ornamental object may be such a basic thing as a paperweight (see below). Also, smaller polished stones can be obtained and things like necklaces, bracelets, and anklets could be made from these smaller specimens. In the gemstone class this semester, we strung beads. This was quite the experience and some beautiful pieces were made and can be seen below.

Sodalite: Ornamental and Jewelry


Image taken from Mineralminers.com.


Image by Kevin Faurot.
© 2005

Look Alikes

Sodalite and its blue color is mainly confused with two substances. The first azurite which has a dark blue color, but is a mineral often times found in a rock with malachite. The second is lapis lazuli, and this rock looks like sodalite because sodalite can be found in lapis. However, the blue color of lapis is more uniform, and it often has pyrite inclusions, not the black and white inclusions in sodalite. Sodalite can also be confused with dumortierite, hauynite, lazulite, and of course, synthetic sodalite.

Origin of Sodalite

Sodalite is usually found in "syenite and trachyte rocks"(Schumann, 1997, p. 174). Most deposits of sodalite are known to be found in Brazil, specifically Bahia. Other occurences are Greenland, India, Canada, Namibia, Russia, and Montana (p. 174).

References

The Mineral Sodalite. mineral.galleries.com/minerals/silicate/sodalite/sodalite.htm, Amethyst Galleries, Inc.
Sodalite. www.bestcrystals.com/sodalite.html, Bestcrystals.com
Sodalite: Mineral Information Page. www.mineralminers.com/html/sodminfo.htm, Mineralminers.com
Schumann, W., 1997. Gemstones of the World. Sterling Publishing Co., Inc. New York.

Site Created April 16, 2005 by Kevin Faurot. Contact me at four_oh_phi434@hotmail.com.

Copyright 2005 Kevin Faurot. All rights reserved.

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