Below is a summary of the available factual information regarding the gemstone Sunstone.
The Gemological and Historical Profile of Sunstone
Sunstone is a member of the feldspar group of minerals, encompassing varieties of both orthoclase and plagioclase feldspar. It is closely related to other feldspar group gemstones, including moonstone, amazonite, and both phenomenal and non-phenomenal labradorite. The gemstone is particularly noted for its resemblance to the sun, often exhibiting a "flash" or chatoyancy caused by reflective inclusions of hematite or goethite.
Gemological Properties
Sunstone is characterized by its distinct optical effects and chemical diversity. A key feature is its aventurescence, a sparkly, metallic-looking luster resulting from flat, reflective inclusions. In the case of Oregon sunstone, the gem is transparent with glittery copper inclusions.
The mineral typically occurs in large masses rather than tabular or prismatic forms. Its color palette is diverse, ranging from peach-pink, bright orange, and light red to yellow, green, red-brown, and colorless. In very rare instances, natural sunstone can be found in dark blue or a translucent ivory green.
Technical Specifications
The scientific properties of sunstone vary based on its specific mineral species:
| Property | Orthoclase Sunstone | Oligoclase Sunstone | Labradorite Sunstone |
|---|---|---|---|
| Chemical Composition | $\text{KAlSi}3\text{O}8$ | $\text{NaAlSi}3\text{O}8$ to $\text{CaAl}2\text{Si}2\text{O}_8$ | $\text{NaAlSi}3\text{O}8$ to $\text{CaAl}2\text{Si}2\text{O}_8$ |
| Refractive Index | 1.518 – 1.526 | 1.537 – 1.547 | 1.559 – 1.568 |
| Birefringence | 0.005 – 0.008 | 0.007 – 0.010 | 0.007 – 0.010 |
| Specific Gravity | 2.58 | 2.65 | 2.70 |
| Mohs Hardness | 6.0 – 7.2 | 6.0 – 7.2 | 6.0 – 7.2 |
History and Origins
Sunstone was discovered in 1837 by J.D. Dana. Over the centuries, significant deposits have been identified in India, Sri Lanka, Mexico, Norway, Russia, China, Canada, and the United States.
The state of Oregon holds a unique historical connection to the gem. Local Native Americans highly revered the mineral as a sacred gift from Mother Earth; historical records indicate that some would bury their deceased with small satchels of sunstone as offerings to the gods. In the early 1900s, Tiffany and Co. began purchasing mining claims in the basalt flows of Oregon, which are known for producing some of the world's finest specimens. On August 4, 1987, sunstone was officially designated as the state gemstone of Oregon. While Oregon remains a source of high-quality, natural, untreated product, much of the sunstone currently on the market originates from deposits in India.
Symbolism and Metaphysical Beliefs
In modern metaphysical contexts, sunstone is believed to resonate with the sacral and solar plexus chakras. It is claimed to help align these centers to revitalize personal energy, passion, creativity, determination, and personal will. Practitioners suggest that the stone's "sunny" rays can imbue the body and aura, facilitating a transformation process and channeling energy through the mental and emotional bodies.