The Mineral COCONINOITE

• Chemistry: Fe2Al2(UO2)2(PO4)4(SO4)(OH)2 - 20H2O , Hydrated Iron Aluminum Uranyl Phosphate Sulfate Hydroxide.
• Class: Phosphates
• Uses: a very minor ore of uranium and as mineral specimens.
• Specimens

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Coconinoite is a rare uranium mineral that is named for the type locality from where it was first described, Coconino Co., Arizona, USA. It is an extremely unusual mineral just by its chemistry alone. Not only does it have the uranyl groups in its chemistry but it also has a sulfate group. Coconinoite is interesting for its good fluorescence under UV light as well. Remember, this is also a radioactive mineral and should be stored away from other minerals that are affected by radioactivity and human exposure should always be limited.

PHYSICAL CHARACTERISTICS:

• Colors are various shades of pale yellow.
• Luster is vitreous or waxy to dull or earthy.
• Transparency crystals are translucent.
• Crystal System is orthorhombic or possibly monoclinic.
• Crystal Habits include crusts, earthy masses, foliated and scaly aggregates.
• Specific Gravity is approximately 2.9 (average for translucent minerals).
• Streak is pale yellow.
• Other Characteristics: radioactive and some specimens are fluorescent.
• Notable Occurrence is Sun Valley Mine, Coconino Co., Arizona, USA.
• Best Field Indicators are color, fluorescence if present, radioactivity and locality.