Coconinoite - Jomac Mine, San Juan County, Utah, USA

Fe³⁺₂Al₂(UO₂)₂(PO₄)₄(SO₄)(OH)₂ · 20H₂O

Coconinoite from the Jomac Mine in San Juan County, Utah, is a rare uranium-phosphate mineral with a distinct chemical formula: Fe³⁺₂Al₂(UO₂)₂(PO₄)₄(SO₄)(OH)₂ · 20H₂O. It typically forms as yellow to yellow-green, powdery coatings or crusts on the surfaces of host rocks, often found in oxidized zones of uranium deposits. At the Jomac Mine, coconinoite occurs as a secondary mineral resulting from the weathering and alteration of primary uranium-bearing minerals. The mineral often associates with other uranium phosphates, such as meta-autunite and torbernite, as well as various iron oxides, which contribute to its distinctive appearance and geological context.

Specimens of coconinoite from this locality are of particular interest to mineral collectors and geologists due to their rarity and vibrant coloration. The Jomac Mine, located in a region historically significant for uranium mining, provides an ideal environment for the formation of such secondary minerals. The mineral’s unique combination of uranium, phosphate, and iron makes it a useful indicator of geochemical processes within oxidized zones. However, its uranium content requires careful handling and storage. Coconinoite’s aesthetic qualities, combined with its scientific importance, make it a prized addition to collections, offering insights into the complex mineralogy of uranium deposits in the southwestern United States.

Approx. activity on an SE International Ranger EXP: 1100 cpm