under longwave
UV light
  • Chemistry: Na2CaUO2(CO3)3-6H2O, Hydrated Sodium Calcium Uranyl Carbonate
  • Class: Carbonates
  • Uses: very minor ore of uranium and as mineral specimens.
  • Specimens

Andersonite is a rare uranyl carbonate mineral, that was only described in the last half century. It has a luster that seems to glow and in fact it is very fluorescent. Andersonite specimens will usually glow a bright lemon yellow in ultraviolet light. The mineral is formed as a secondary mineral and as an efflorescent crust in uranium mines. Efflorescent means it forms on the surface of a rock by the evaporation of water when in contact with the dry air of the mine. Thus, some andersonite specimens are the result of human intervention (albeit unintentional) and some mineralogists do not consider these to be pure mineral specimens.

Andersonite's lovely color and unique glow, as well as it's rarity and fluorescence, make it a wonderful mineral for rare mineral collectors. Remember, this is a radioactive mineral and should be stored away from other minerals that are affected by radioactivity and human exposure should definitely be limited.


  • Color is yellow to a yellowish green.
  • Luster is vitreous to pearly.
  • Transparency crystals are commonly translucent.
  • Crystal System is trigonal.
  • Crystal Habits include small rhombohedral crystals that have angles close to 90 degrees, making them pseudocubic. Also found commonly as crusts.
  • Cleavage is perfect in three directions forming rhombs.
  • Fracture is conchoidal.
  • Hardness is 2.5
  • Specific Gravity is 2.9 (average).
  • Streak is pale yellow.
  • Associated Minerals are gypsum and other uranium carbonates such as bayleyite, Mg2(UO2)(CO3)3-18H2O and liebigite, Ca2(UO2)(CO3)4-11H2O.
  • Other Characteristics: radioactive, and fluoresces bright lemon-yellow under ultraviolet light.
  • Notable Occurrences include the Hillside Mine, Bagdad, Arizona and the Jim Thorpe Mine, Pennsylvania, USA.
  • Best Field Indicators are its crystal habit, radioactivity, fluorescence and associations.
ANDERSONITE specimens:
(hover for more info)
ANDERSONITE specimen ane-1
$ 120.00
Dims: 4" x 2-1/2" x 1/2"
Wt: 3.3 oz
Moab, Utah, U.S.A.
Spread out on a nondescript, gray/beige slab of what appears to be a shale or mudstone is a massive crust of Andersonite. The crust is very thin (about 1 mm or so), and covers approximately half of one side of the shale/mudstone host rock. Its color is a rather dull yellow with a hint of green, and under 15x magnification, I can detect no crystalline structure. Just get this little lovely under a longwave UV source, though, and the beauty comes shining through; the color that will show is greener than what is displayed in our "fluorescence picture". It is a really good fluorescing specimen, though, and is rather uncommon, or so I've read.
no photo
ane-1 ($120.00)
Moab, Utah, U.S.A.
ANDERSONITE specimen ane-2
$ 25.00
Dims: 2.0" x 1.1" x 0.9"(5.1 x 2.8 x 2.3 cm)
Wt: 22.0 g
Cane Springs Canyon, San Juan County, Utah, U.S.A.
A thin crust of bright yellow Andersonite partially covers the sandstone host rock of this specimen. It exhibits no crystal form, has a dull luster, and is probably translucent, but lays flush against the host rock, so there is no way to verify it. It does, however, glow a bright green under shortwave UV radiation. This specimen is appropriate for the collector of uranium minerals that doesn't have a lot of money to spend on them.
no photo
ane-2 ($ 25.00)
Cane Springs Canyon, San Juan County, Utah, U.S.A.
ANDERSONITE specimen ane-3
$ 50.00
Dims: 3.5 x 2.3 x 2.0" (8.9 x 5.8 x 5.1 cm)
Wt: 8.13 oz. (230.7 g)
Kane Springs Wash, San Juan County, Utah, U.S.A.
This hand specimen consists of a chalky, pale brown sandstone host rock on which rest several small, very thin crusts of massive Andersonite. Even under 10-power magnification I cannot detect any crystal form or crystalline tendencies. The crusts have a bright yellow color with a hint of green and a dull waxy luster. When bathed with shortwave ultraviolet radiation, the Andersonite glows a bright pale blue-green coloration. There are several patches of this material scattered around the host rock.
no photo
ane-3 ($ 50.00)
Kane Springs Wash, San Juan County, Utah, U.S.A.
ANDERSONITE specimen ane-4
$ 48.00
Dims: 3.3 x 2.1 x 1.9" (8.4 x 5.3 x 4.8 cm)
Wt: 9.43 oz. (267.5 g)
Kane Springs Wash, San Juan County, Utah, U.S.A.
This hand specimen consists of a chunk of pale brown sandstone that is partly coated with a few small, thin Andersonite crusts. These crusts are made up of massive Andersonite- thus, no crystal form is evident. The material has a bright yellow color with a faint hint of green and a dull luster, and is possibly translucent, though this is extremely difficult to determine. As can be seen in the second image, it glows a bright, aqua-blue color when bathed in shortwave ultraviolet light.
no photo
ane-4 ($ 48.00)
Kane Springs Wash, San Juan County, Utah, U.S.A.
ANDERSONITE specimen ane-5
$ 25.00
Dims: 1.5 x 1.2 x 1.0" (3.8 x 3.0 x 2.5 cm)
Wt: 21.2 g
Ambrosia Lake Deposit, Valencia County, New Mexico, U.S.A.
This specimen consists of an incomplete Andersonite crust that partly coats a granular, pale brown base rock. This crust is one of the thicker ones that I have seen, and is flat and has general dimensions of 1.5 x 1.2 x 0.1" (3.8 x 3.0 x 0.3 cm). The crust is composed of many small, heavily-intergrown crystals- though none of these crystals are really definable, one can see definite crystalline tendendies both on its natural and breakage surfaces. It has the standard bright yellow coloration of Andersonite, and though its natural surfaces are dull, its breakage surfaces betray a pearly luster. It glows a bright aqua-blue coloration under shortwave ultraviolet light, as can be seen in our second image. The base rock appears to be made of a sandstone, and is nondescript.
no photo
ane-5 ($ 25.00)
Ambrosia Lake Deposit, Valencia County, New Mexico, U.S.A.
ANDERSONITE specimen ane-6
$ 29.00
Dims: 1.6 x 1.6 x 0.9" (4.2 x 4.0 x 1.9 cm)
Wt: 1.1 oz. (32 g)
Atomic King Mine, near Moab, San Juan County, Utah, U.S.A.
A few bits of a massive Andersonite crust rest on the grainy, pale brown host rock of this hand specimen. The Andersonite shows no crystal form and has the classic bright yellow coloration and waxy luster of its specie.
no photo
ane-6 ($ 29.00)
Atomic King Mine, near Moab, San Juan County, Utah, U.S.A.
ANDERSONITE specimen ane-7
$ 95.00
Dims: 3.74x2.72x2.01" (9.5x6.9x5.1cm)
Wt: 10.85oz (307.0g)
Atomic King Mine, San Juan County, Utah, USA
Several thin crusts of yellow andersonite adorn this non-descript host rock. More andersonite resides in veins that penetrate it. While these crusts appear crystalline, I cannot determine their shape even with the aid of a loupe. They appear opaque, and have a dull luster. Under ultraviolet light, the andersonite glows a very bright lemon yellow, and indeed this reveals even more of the mineral on this specimen, as some areas glow that looked devoid of andersonite to the naked eye.
no photo
ane-7 ($ 95.00)
Atomic King Mine, San Juan County, Utah, USA
ANDERSONITE specimen ane-8
$ 57.00
Dims: 2.21x1.54x1.04" (5.61x3.90x2.63cm)
Wt: 1.59oz (45.0g)
Atomic King Mine, San Juan County, Utah, USA
In normal light, the andersonite on this specimen is a barely visible thin yellow crust on the surface. It it more visible in sunlight, and is present on most of the spcimen's surfaces. Under UV, however, it glows a bright and unmistakable blue, and every tiny patch of andersonite can be easily identified.
no photo
ane-8 ($ 57.00)
Atomic King Mine, San Juan County, Utah, USA
ANDERSONITE specimen ane-9
$ 55.00
Dims: 3.39x1.37x0.59" (8.60x3.49x1.50cm)
Wt: 2.08oz (59.0g)
Atomic King Mine, San Juan County, Utah, USA
A non-descript piece of rock has green, sparkly crystals on its edges, especially on the front with a lessor amount on the back. This is andersonite, in the form of green, translucent crystals. Their color is excellent, but their form is lacking, as there are few distinct crystals with clean surfaces, yet it does appear crystalline and the sparkle is due to a vitreous luster. Under UV light, the andersonite comes alive witha bright blue-green glow, which also locates more areas and even veins of massive andersonite on the specimen.
no photo
ane-9 ($ 55.00)
Atomic King Mine, San Juan County, Utah, USA


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