Other Structural Phenomena
“Other Structural Phenomena” in gemstones refers to the unique and lesser-known features within the internal structure of a gem that contribute to its overall appearance, value, and identification. Unlike widely recognized characteristics such as color, clarity, cut, and carat weight, these phenomena stem from the gemstone’s formation process, inclusions, or crystal lattice irregularities. They can include asterism (the star effect), chatoyancy (the cat’s eye effect), play-of-color (seen in opals), adularescence (a soft glow similar to moonstone), iridescence (rainbow colors seen in certain angles), and labradorescence (the metallic iridescence in labradorite). Each of these phenomena can enhance a gemstone’s beauty and rarity, making it more sought after by collectors and enthusiasts. Understanding these phenomena requires a deep knowledge of gemology and the science of gemstone formation, as they can significantly influence the gemstone’s market value and appeal.
Asterism: Caused by light reflecting off of parallel inclusions, creating a star effect on the gem’s surface
Asterism is a captivating optical phenomenon and one of the “Other Structural Phenomena” observed in certain gemstones, notably sapphires and rubies, where a star-like pattern appears on their surface due to the interaction of light with parallel inclusions inside the gem. These inclusions, often made of rutile minerals, reflect or refract light, creating a star with four, six, or twelve rays that seems to move across the stone’s surface with the light source. This effect, best seen under a single light source, highlights the unique internal structure of the gemstones and results from a precise natural alignment of inclusions. Star sapphires and star rubies, adorned with this phenomenon, are especially valued for their rarity and the mesmerizing visual effect they offer. Each asteriated gemstone is distinct, with variations in the star’s clarity, orientation, and visibility, making them not just jewels but natural art pieces that embody celestial beauty. Our collection features these gems, inviting admirers to explore the enchanting interplay of light and shadow that brings the illusion of a serene starry night to life within the confines of a precious stone. This phenomenon, alongside others like chatoyancy and play-of-color, showcases the diverse and intricate ways in which the internal structure of gemstones can manifest as breathtaking visual effects.
Chatoyancy: The “cat’s eye” effect caused by inclusions
Chatoyancy, known as the ‘cat’s eye’ effect, is an optical phenomenon in certain gemstones, creating a visual effect similar to the eye of a cat. This effect arises from light reflecting off parallel fibrous or needle-like inclusions within the gemstone or its internal fibrous structure. The interaction of light with these inclusions or structures produces a concentrated, shifting band of light, leading to a dynamic and captivating appearance. Commonly found in chrysoberyl, tiger’s eye, and some quartz varieties, the quality of chatoyancy can vary, with the most valued gems displaying a strong, clear, and centered cat’s eye effect. These gemstones are particularly prized for their uniqueness and are often cut into cabochons to best showcase their mesmerizing effect. Our collection highlights a variety of chatoyant gemstones, offering a glimpse into the intriguing interplay of light and the complex internal structure of these natural artworks, inviting enthusiasts to discover their mysterious and enchanting beauty.
Horsetail Inclusions: Radiating inclusions seen particularly in demantoid garnet.
Horsetail inclusions are a remarkable and sought-after characteristic in gemology, especially valued in demantoid garnets. These inclusions, which resemble the strands of a horsetail emanating from a central point within the gemstone, contribute to the rarity and appeal of demantoid garnets. Originating deep within the Earth under specific conditions, demantoid garnets featuring horsetail inclusions highlight the intricate processes behind gemstone formation. Composed mainly of chrysotile or byssolite, these inclusions not only add visual interest but also verify the gemstone’s authenticity and geographical origins, often indicating a connection to Russia’s Ural Mountains.
The allure of horsetail inclusions, a fascinating example of “Other Structural Phenomena,” lies in their fine, detailed pattern, which becomes apparent under magnification, adding to the gemstone’s natural beauty. In the realm of demantoid garnets, the presence of distinct horsetail inclusions is sometimes more desirable than a gemstone without flaws, as it emphasizes the stone’s natural, unaltered state. Our collection highlights demantoid garnets with horsetail inclusions, celebrating these natural phenomena as geological artwork. Each piece invites admiration of the unique patterns created by the inclusions, offering a glimpse into the extraordinary natural forces that form the Earth’s gemological treasures, alongside other structural phenomena that contribute to their allure and value.