Ethiopian opal, 5.841 carats

Technical details: Type: Ethiopian Opal (Opal) Weight: 5.841 carats Shape: Cabochon (Cabochon) Color: Black and multicolored Clarity: Unclassified (Uncategorized) Transparency: Opaque (Opaque) Hardness: 5.5-6.5 Treatment: Smoke Treated Origin: Ethiopian Certification: Electronic certificate (PDF) from Saudi Laboratory (MT) - Website (www.mtgl.com.sa) Opal is a semi-precious (amorphous) mineral of Hydrated Silica, known for its great diversity in appearance. The most famous type is Precious Opal, which features a unique optical phenomenon called play-of-color, where iridescent flashes of different spectral colors change with the angle of view, due to light interference with microscopic silica spheres. Common Opal, on the other hand, does not show this phenomenon but comes in a variety of colors. Opal forms in cavities of sedimentary and volcanic rocks when silica-rich water solutions are deposited.