Jewelry New Arrivals Pairs Lots Contact
  : Obsidian Info

Obsidian Gemstone Information

About Obsidian - History and Introduction

Obsidian is naturally occurring volcanic glass which has been used as a gemstone since antiquity. Obsidian was named after Obsius, a Roman who discovered a similar stone. Obsidian forms when lava cools and whilst it is mineral-like, it is not considered to be a true mineral because its composition is too complex and it does not have a crystalline structure. In addition to its decorative use, obsidian has a practical use. Due to its lack of cleavage, conchoidal fracture and acute edges when broken, it has been used to make smooth and sharp surgical scalpel blades. Obsidian has been used to make arrow heads and blades, as well as ornaments for thousands of years by people such as the pre-Columbian Mesoamericans and the ancient Egyptians.

In its pure form, obsidian has a dark body colour due to the presence of iron and magnesium. Obsidian can be classified into types according to a variety of characteristics. However, some basic types of obsidian include the following: Mottled (snowflake and peanut obsidian), banded or veined (Mahogany, midnight lace and pumpkin obsidian), pebbles or small nodules (Apache tears) and sheen (sheen obsidian, cat's eye, rainbow and fire/flame obsidian).

Gold-Sheen Obsidian
Gold-Sheen Obsidian
Identifying Obsidian Back to Top

Obsidian can be identified by its glassy lustre and single refraction.

Obsidian; Origin and Gemstone Sources Back to Top

Obsidian is found in places that have experienced volcanic eruptions. Such places include Argentina, Armenia, Azerbaijan, Canada, Chile, Georgia, Greece, El Salvador, Guatemala, Iceland, Italy, Japan, Kenya, Mexico, New Zealand, Peru, Scotland, Turkey and the United States.

Buying Obsidian and Determining Obsidian Gemstone Value Back to Top

Obsidian Colour

Pure obsidian is a very dark colour. It gets this colour from the presence of iron and magnesium. Colourless obsidian is rare. Mahogany obsidian has dark-brown to black and red banding. Sheen obsidian is dark-brown to black with a golden or silver sheen (this is also called aventurescence). Rainbow obsidian is dark-brown to black with an iridescent sheen. The iridescence of obsidian can be gold, silver, blue, violet, green or combinations of these colours. The rainbow colours of rainbow obsidian come from the presence of augitic pyroxene. "Fire" or "flame" obsidian reflects bright colours due to the presence of nanometric magnetite crystal layers. Transparent pale yellow-green to brownish obsidian from Peru is referred to as macusanite. Translucent to opaque, black-streaked orange, red or brown obsidian nodules from the American Southwest are known as "Apache tears". Orange obsidian is referred to as "pumpkin obsidian" and plum-coloured obsidian is called "plum obsidian".

Obsidian Clarity and Lustre

Since obsidian is volcanic glass, it has a vitreous (glassy lustre). It may contain inclusions which cause a silver or gold sheen. It may also contain needle-like inclusions, gas bubbles, torpedo-shaped bubbles, teardrop-shaped bubbles or cristobalite crystal inclusions, which appear like "snowflakes" in "snowflake obsidian". Obsidian from Chile has also been found containing very rare inclusions of euhedral indialite crystals and transparent rods of sillimanite. Bolivian obsidian has been found to contain orange spessartine inclusions. Obsidian can display chatoyancy (cat's eye effect).

Obsidian Cut and Shape

Due to the opacity of most types of obsidian, it is usually cabochon cut, fancy cut, sphere-cut, tumbled, made into cameos or carved. Cabochon cuts also best exhibit any sheen or iridescence. Translucent to transparent materials are faceted.

Obsidian Treatment

Obsidian is not usually treated or enhanced in any way.

Obsidian Gemmological Properties: Back to Top
Chemical Formula/Composition: 70-75% SiO2 + MgO, Fe3O4 Volcanic, amorphous, siliceous glassy rock
Crystal Structure: None
Colour: Black, grey, brown, orange; rarely green, red or blue
Hardness: 5 - 5.5 on the Mohs scale
Refractive Index: 1.45 - 1.55
Density: 2.35 - 2.60
Cleavage: None
Transparency: Transparent to opaque
Double Refraction or Birefringence: None
Lustre: Vitreous
Fluorescence: None

Please refer to our Gemstone Glossary for details of gemmology-related terms.

Obsidian: Related or Similar Gemstones Back to Top

Obsidian has some similarities to quartz, due to its silicon dioxide content. However, quartz is a harder material than obsidian, at 7 on the Mohs scale, whereas obsidian has a hardness of 5 to 5.5. Additionally, obsidian has a lower density and refractive index than quartz. Also, obsidian is singly refractive whereas quartz is doubly refractive. Obsidian can appear similar to hematite, aegirine-augite, gadolinite, pyrolusite and wolframite, which all have a higher density than obsidian. Jet can also appear similar to obsidian, but it is a softer substance.

Obsidian Gemstone Mythology, Metaphysical and Alternative Crystal Healing Powers Back to Top

Obsidian is thought to be a powerful stone that can offer protection against negativity. It is sometimes called "the stone of truth" because it encourages the surfacing of secrets and hidden emotions. Additionally, obsidian is also thought to be a balancing and grounding stone. Traditional Indian belief systems associate obsidian with the root chakra, which governs sexuality and stability. Centuries ago, black obsidian mirrors were used to contact the spirit world, and it is thought to be useful in resolving issues related to past lives. Obsidian is also considered to be particularly useful for those suffering from depression or addiction.

Disclaimer: Metaphysical and Alternative Crystal Healing Powers and Properties are not to be taken as confirmed advice. Traditional, Ceremonial and Mythological Gemstone Lore is collected from various resources and does not represent the sole opinion of SETT Co., Ltd. This information is not to replace the advice of your doctor. Should you have any medical conditions, please see a licensed medical practitioner. GemSelect does not guarantee any claims or statements of healing or astrological birthstone powers and cannot be held liable under any circumstances.
Obsidian Gemstone and Jewellery Design Ideas Back to Top

Obsidian's beautiful natural dark, glossy colour makes it fashionable for both young and old, male and female. Obsidian gemstones make for a dramatic, high-fashion look. They can be fashioned into vintage, gothic, Celtic and punk-inspired designs, or modern, edgy pieces.

Obsidian is often set in silver, which provides an attractive contrast to its dark colour. The versatility of obsidian allows it to be fashioned into a wide variety of jewellery, such as beads for bracelets and necklaces, cabochons for pendants and rings, or carved pieces that are used for pendants and other items. The shiny glassy lustre of black obsidian means that it looks good both faceted and as smooth cabochons. Obsidian arrowheads are also made into striking tribal-style rings or necklace and earring pendants, which have a dramatic look when set in gold.

Note: Buy coloured gemstones by size and not by carat weight. Coloured stones vary in size-to-weight ratio. Some stones are larger and others are smaller than diamonds by weight in comparison.

Famous Obsidian Gemstones Back to Top

Dr Dee's mirror is a highly polished piece of obsidian which was used as an occult research tool by Elizabethan mathematician, astrologer and magician, John Dee (1527 - 1608/9). It was originally an Aztec cult object and is on display at The British Museum.

Some of the pupils of the eyes of the "Moai" (statues of human figures) on Easter Island that were carved between 1250 and 1500, were made from obsidian.

The Necklace of Renisenib; a gold and obsidian necklace, dated at around 1810 - 1700 BC, was excavated from the Nile Valley by Howard Carter and Lord Carnarvon in 1910 and is now displayed at the New York Metropolitan Museum of Art.

Brooklyn Museum, USA, displays various pieces of obsidian in its exhibition of Ancient Egyptian Fragments and Amulets, such as the eye from a coffin and a two finger amulet that would have been placed on a mummy to protect the deceased.

Obsidian Gemstone Jewellery Care and Cleaning Back to Top

Although obsidian has a hardness of 5 - 5.5 on the Mohs scale, which is How to clean your gemstonessofter than quartz, it is a durable material. To clean your obsidian, simply use soapy water and a soft cloth. Be sure to rinse well to remove soapy residue. As with most gemstones, ultrasonic cleaners and steamers are not recommended. Always remove any jewellery or gemstones before exercising, cleaning or engaging in harsh physical activities such as sports. Obsidian can be easily scratched by harder substances, so it should be stored away from other gemstones. It is best to wrap gemstones in soft cloth or place them inside a fabric-lined jewellery box.

  • First Published: February-28-2014
  • Last Updated: May-30-2014
  • © 2005-2017 all rights reserved.
    Reproduction (text or graphics) without the express written consent of (SETT Company Ltd.) is strictly prohibited.
English speaking customer support only

Toll Free - USA & Canada only:


Reorder Items

Save Money
No shipping Fees for Additional Items!
$6.99 Worldwide Shipping

GemSelect Gemstones
X Close Window
Colored Gemstones
X Close Window
Colored Gemstones
X Close Window
Colored Gemstones
Size and Weight

Gems are always measured in Millimeter (mm)

Dimensions are given as;
length x width x depth,
except for round stones which are;
diameter x depth

Select gems by size, not by weight!
Gem varieties vary in density, so carat weight is not a good indication of size

Note: 1ct = 0.2g

Size Comparison Chart