Unleash the power of a roaring fire with our bestselling Black Fire Astral Opal™ Cabochons. This iconic lab-created Astral Opal™ features a deep black base that smolders with intense flashes of red, orange, and green fire. Their perfectly calibrated round shape and flat back make them ideal for precise setting and inlay work. As our most popular choice for jewelry making supplies, these synthetic Astral Opal™ cabochons bring an unmatched energy and burning passion to your most important projects, from bold ring settings to fiery stud earrings. Product Specifications Material Lab-Grown Astral Opal™ (80% Silica, 20% Polymer) Color Play Primary: Deep Black | Fire: Rainbow (Red, Orange, Green) Shape Round Cabochon Back Flat Back Sizes 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm Quantity Sold by the Individual Cabochon Hardness 4 on the Mohs scale Heat Resistance Up to 250°F / 120°C Sizing & Thickness 2mm Cabochon: 1.0mm Thick 3mm Cabochon: 1.5mm Thick 4mm Cabochon: 1.8mm Thick 5mm Cabochon: 2.0mm Thick 6mm Cabochon: 2.2mm Thick 7mm Cabochon: 2.4mm Thick 8mm Cabochon: 2.6mm Thick Why Choose Our Astral Opal™ Cabochons? Intense Fire & Color: Meticulously grown to display a fiery and brilliant spectrum of color flashes against a smoldering dark base. Perfectly Calibrated: Each cabochon is cut to precise millimeter dimensions with a flat back, ensuring a perfect fit for bezels, settings, and inlay channels. Unmatched Stability: Guaranteed not to crack, craze, or yellow over time, offering superior durability over natural Astral Opal™. Easy to Set & Polish: The smooth, domed top polishes to a high shine, and the flat back provides maximum surface area for adhesives, making them ideal for jewelry of all kinds. Creative Applications Jewelry Setting: The top choice for creating passionate, eye-catching jewelry. Set them in bezels for bold rings, smoldering pendants, and statement earrings. Nail Art & Adornment: Add a fiery, gem-like accent to create dramatic and high-end nail art designs. Surface Inlay: Ideal for inlaying into woodworking and other crafts to create a dramatic 'lava flow' or galaxy effect. Wire Wrapping: Use as a powerful centerpiece for wire-wrapped designs that demand attention. Please Note: Our lab-created Astral Opal™s can withstand heat up to approximately 250°F. For best results and to maintain the integrity of your cabochons, please avoid exposing them to high heat. Due to their unique composition, every cabochon is unique and color may vary.