Arizona Blue Opal — The Rare Gemstone of Southern Arizona

Arizona Blue Opal is an unusual gemstone found in the mountains of southern Arizona, particularly in Santa Cruz County near the historic mining community of Ruby and the town of Tubac.

Unlike the better-known Australian opals, Arizona Blue Opal is prized for its distinctive blue coloring, natural landscape-like patterns, and occasional flashes of rainbow color.

It is also marketed under the name Southern Skies Opal, associated with jewelry artist VinCent Gulino.

What makes Arizona Blue Opal special?

  • Origin: Southern Arizona, particularly the Atascosa Mountains and surrounding mining districts.

  • Color: Pale sky blue, robin's-egg blue, gray-blue, and deeper blues, often accompanied by brown, pink, cream, or reddish matrix.

  • Formation: Silica-rich fluids deposited opal within volcanic rock, including rhyolite.

  • Hardness: Generally around 5.5–6.5 on the Mohs scale, although Southern Skies reports some material as high as 7.

  • Appearance: Some stones display natural patterns resembling desert mountains, clouds, rivers, and miniature landscapes.

  • Rarity: Material with vivid blue coloring and strong rainbow flashes is relatively uncommon.