Green obsidian is a type of natural glass that gets its name from its green color. The green hue arises from trace elements like iron and chromium, sometimes enhanced by gas bubbles trapped within the rock, creating a beautiful sheen or iridescence. It is a rare and valuable gemstone that is found in only a few places in the world, including Mexico, Guatemala, and the United States.
Obsidian is a naturally occurring volcanic glass. It is formed during the eruption of felsic lavas, which are distinguished by having high concentrations of the chemical element silica. Because of their high silica content, felsic lavas do not behave like the mafic, or silica-poor, lavas we see on the island of Hawaii.
Green Obsidian is one of obsidian rocks that contain impurities. Iron and other elements of transition can give a dark brown to black color to the obsidian. Most black obsidians contain magnetite, an iron oxide, nanoinclusions, the composition of obsidian is extremely felsic.
Elmerite is a trade name given to a green form of obsidian discovered in Ethiopia in 2016.
|Natural Green Obsidian Volcanic.
Pure obsidian is usually dark in appearance, though the color varies depending on the presence of impurities. This can be caused by tiny microscopic inclusions of other minerals (feldspar, amphibole, biotite, quartz) called microlites (not the mineral). They can be observed under a microscope as thin rectangular, sometimes equant crystals that can sometimes form bands and give obsidian its characteristic colour.
In the case of dark green obsidian the colouration is caused varying amounts of Fe and Mg. The green coloration can also be achieved as some gas bubbles (vescicles) remained in the lava flow during crystallization.
Obsidian consists mainly of SiO2 (silicon dioxide), usually 70% or more. Crystalline rocks with obsidian's composition include granite and rhyolite. Because obsidian is metastable at the Earth's surface (over time the glass becomes fine-grained mineral crystals), no obsidian has been found that is older than Cretaceous age.
Green Obsidian is also used for ornamental purposes and as a gemstone. It presents a different appearance depending on how it is cut: in one direction it is jet black, while in another it is glistening gray. "Apache tears" are small rounded obsidian nuggets often embedded within a grayish-white perlite matrix.
|Green Obsidian from Davis Creek in Northern California, USA
Green Obsidian Uses
Eye-catching adornment: The vibrant green color and occasional sheen make green obsidian a popular choice for cabochons, beads, pendants, and rings. Its unique beauty adds a touch of intrigue and elegance to any jewelry collection.
Versatility: It complements various styles, from bohemian to contemporary, making it a versatile gem for different personalities and tastes.
Metaphysical and Healing:
Emotional healing and balance: Green obsidian is often associated with emotional healing and growth. It's believed to help release negativity, foster inner peace, and promote emotional balance. Many use it during meditation or hold it close to facilitate emotional well-being.
Spiritual connection and protection: Some believe green obsidian strengthens the connection with nature and facilitates spiritual growth. It's also associated with protection from negative energies and psychic attacks, offering a sense of grounding and stability.
Art and decoration: The captivating beauty of green obsidian extends beyond jewelry. Its unique color and properties make it a valuable material for sculptures, figurines, and even ornamental objects, adding a touch of magic to any space.
Collectibles: Due to its rarity and alluring features, green obsidian is sought after by mineral and gemstone collectors. Its mesmerizing color and potential metaphysical properties add to its value as a collector's item.
|Natural Green Obsidian
Green Obsidian Properties
Category: Igneous rock, specifically a volcanic glass formed from rapidly cooled lava.
Color: Deep emerald green, sometimes with a subtle sheen or iridescence. The color variations can range from near black with green flashes to a vibrant, almost apple-green hue.
Texture: Smooth and glassy, lacking the crystalline structure of typical minerals.
Hardness: 5-5.5 on the Mohs scale, making it moderately durable for jewelry but susceptible to scratches.
Transparency: Translucent to opaque, depending on the stone's thickness and clarity.
Mineral composition: Primarily silicon dioxide (SiO₂) with trace elements like iron (Fe) and chromium (Cr) contributing to its green color.
Streak: White, similar to most glasses, regardless of the stone's surface color.
Composition: Volcanic glass, formed by the rapid cooling and solidification of molten lava.
Cleavage: Conchoidal, meaning it fractures with smooth, curved surfaces like a seashell.
Fracture: Brittle, meaning it can break easily with sharp blows or sudden pressure changes.
Density: Around 2.4 g/cm³, slightly lighter than its black obsidian counterpart.
Weathering resistance: Moderately resistant to weathering, although prolonged exposure to harsh elements like sunlight and acidic rain can cause surface dulling or discoloration.
Magnetism: Non-magnetic due to its lack of iron in the form of magnetite.
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