Opal

About

Opal Crystals Opal is a hydrated amorphous silica (SiO₂·nH₂O) containing 3–21% water within its structure. Unlike most gemstones, opal is non-crystalline. Its famous play of color — the shifting rainbow flashes — is caused by diffraction of light through a regular array of silica spheres. When these spheres are uniform in size (150–400 nanometers), white light diffracts into spectral colors. Opal rates 5.5–6.5 on the Mohs scale. The main varieties include white opal (light body color), black opal (dark body, most valuable, from Lightning Ridge, Australia), boulder opal (thin layer on ironstone), fire opal (transparent orange from Mexico), and pink and blue opal from Peru. Australia produces approximately 90% of the world's precious opal. Ethiopian hydrophane opal has become a significant source since 2008. Our collection features pink opal, blue opal, and precious opal in various forms including raw specimens, polished pieces, towers , and bracelets . For other iridescent stones, see our labradorite and moonstone collections. Browse crystal jewelry for opal pendants. Free shipping on orders $150+. Frequently Asked Questions What causes opal's play of color? Play of color is caused by light diffracting through a regular three-dimensional array of silica spheres within the opal. When these spheres are uniform in size and tightly packed, white light splits into spectral colors. The size of the spheres determines which colors appear — smaller spheres produce blues, larger ones produce reds. What are the different types of opal? White opal (light body with play of color), black opal (dark body, most valuable), boulder opal (thin layer on ironstone matrix), fire opal (transparent orange, may lack play of color), Ethiopian opal (hydrophane, absorbs water), and common opal (no play of color, found in pink, blue, and other colors). How should I care for opal? Opal contains water and can crack if it dries out too quickly. Store away from direct heat and prolonged sunlight. Do