THE
MINERAL AJOITE
- Chemistry: (K, Na)Cu7Al(Si3O8) 3(OH)6 - 3H2O, Hydrated Potassium Sodium Copper Aluminum Silicate Hydroxide
- Class: Silicates
- Subclass: Phyllosilicates?
- Uses: A very minor ore of copper and as mineral specimens.
Specimens
Ajoite is an attractive copper silicate mineral that is named for its type locality in the Ajo District of Pima County, Arizona. It is a secondary mineral that forms from the oxidation of other secondary copper minerals.
Ajoite forms excellent microcrystal specimens. The small prismatic crystals are often arranged in tufts with an almost aquamarine-like blue green color. It is associated with other rare and colorful minerals such as shattuckite, copper, papagoite and plancheite; which makes specimens even more attractive.
The color variety in a single multi-mineral specimen is sometimes surreal. Massive samples of ajoite are also unique and are sometimes carved or tumbled and can be used as an ornamental stone. Ajoite's classification as a phyllosilicate is questionable as its true structure is as yet unknown.
PHYSICAL CHARACTERISTICS:
- Color is blue-green to light green.
- Luster is dull to vitreous.
- Transparency specimens are transparent to translucent.
- Crystal System is triclinic, bar 1.
- Growth Habits include acicular to thin prismatic crystals often found as spherules or sprays of acicular radial crystal clusters and as massive specimens.
- Cleavage is perfect.
- Hardness is 3.5.
- Specific Gravity is approximately 2.9 - 3.0 (average for non-metallic minerals).
- Streak is pale greenish white.
- Associated Minerals are quartz,
limonite,
mimetite,
phoenicochroite , willemite,wickenburgite , shattuckite, copper, papagoite, plancheite, duftite and other secondary copper minerals. - Notable Occurrences are limited to the New Cornelia Mine, Ajo District, Pima County and Wickenburg, Maricopa County, Arizona, USA and the Messina District, South Africa.
- Best Field Indicators are color, crystal habit, locality and associations.
 Amethyst Galleries' Mineral Gallery MINERALS |
AJOITE specimen ajo-1
$ 25.00
$ 25.00
Dims: 1.3 x 1.1 x 0.7" (3.2 x 2.8 x 1.8 cm)
Wt: 12 g
New Cornelia Pit, Ajo, Pima County, Arizona, U.S.A.
A mixture of massive Ajoite and shattuckite make up part of the mass of this thumbnail piece. Neither of these materials shows any crystal form, but they are rather easy to discern from each other- the shattuckite shows its classic deep blue color, whereas the Ajoite has a definite blue-green coloration. Both have a dull luster and are translucent at best. The granodiorite host rock on which they rest is rough and has a pink-brown coloration.
ajo-1 ($ 25.00)
New Cornelia Pit, Ajo, Pima County, Arizona, U.S.A.
AJOITE specimen ajo-2
$ 28.00
$ 28.00
Dims: 2.6 x 2.3 x 1.5" (6.6 x 5.8 x 3.9 cm)
Wt: 5.0 oz. (143 g)
New Cornelia Mine, Ajo, Pima County, Arizona, U.S.A.
Veins of massive and crystalline Ajoite permeate the pale brown host rock of this cabinet piece. Only a few tiny, triclinic needles are visible in a few places- these do not exceed 1 mm in length- whereas the rest of the material is massive. It all has the standard bright turquoise-blue coloration and a generally matte luster, though the tiny crystals are pearly.
ajo-2 ($ 28.00)
New Cornelia Mine, Ajo, Pima County, Arizona, U.S.A.
AJOITE specimen ajo-3
$ 25.00
$ 25.00
Dims: 3.0 x 1.7 x 0.8" (7.5 x 4.4 x 1.9 cm)
Wt: 2.0 oz. (57 g)
New Cornelia Mine, Ajo, Pima County, Arizona, U.S.A.
A few small crusts of specular, nearly spiky and massive Ajoite rests on the red base rock of this large hand specimen. Some of them contain intergrown but definite triclinic crystals in radiating sprays, and some show no crystal form at all. All, however, have the bright turquoise-blue coloration that is standard for the specie. Luster ranges from pearly (crystalline) to matte (massive).
ajo-3 ($ 25.00)
New Cornelia Mine, Ajo, Pima County, Arizona, U.S.A.
AJOITE specimen ajo-4
$ 40.00
$ 40.00
Dims: 3.6 x 2.0 x 1.7" (9.2 x 5.0 x 4.2 cm)
Wt: 4.9 oz. (138 g)
New Cornelia Mine, Pima County, Arizona, U.S.A.
Veins of Ajoite and related copper minerals extend through the brown matrix rock of this cabinet piece. The Ajoite appears to be almost completely massive in form - a few tiny patches show a faint sparkling as evidence of nearly microscopic crystal form. It has a blue-green color and a matte luster where massive, but likely a pearly luster where crystals have formed. These crystals are far too small to effectively study even with a loupe - a microscope is needed. The Ajoite also appears to be opaque where massive - I cannot discern the clarity of the crystalline material. Another copper mineral with a pale blue coloration is closely associated in the veins; I am thinking that it could be shattuckite.
ajo-4 ($ 40.00)
New Cornelia Mine, Pima County, Arizona, U.S.A.
AJOITE specimen ajo-5
$ 27.00
$ 27.00
Dims:2.2x1.1x1.1" (5.6x2.8x2.8 cm)
Wt: 2.3oz. (65g)
New Cornelia Mine, Ajo, Pima cty., Arizona
The matrix of this specimen has a scattered thin crust of ajoite crystals with minor shattuckite. These crystals are so small that even with a loupe they cannot be effectively studied. There is no damage to this specimen.
ajo-5 ($ 27.00)
New Cornelia Mine, Ajo, Pima cty., Arizona
AJOITE specimen ajo-6
$ 25.00
$ 25.00
Dims:2.2x1.8x1.2" (5.6x4.6x3.0 cm)
Wt: 3.0oz. (86g)
New Cornelia Mine, Ajo, Pima cty., Arizona
The surface of this specimen is scattered with tiny blue-green clusters of acicular ajoite crystals. In places these clusters have grown together to form a thin crust. Also, there are two tiny vugs in which the radial sprays of ajoite crystals are three-dimensional, rather than the two-dimensional material found on the surfaces of this specimen. There is no noticeable damage at all to this specimen.
ajo-6 ($ 25.00)
New Cornelia Mine, Ajo, Pima cty., Arizona
AJOITE specimen ajo-7
$ 30.00
$ 30.00
Dims:3.2x2.6x1.3" (8.1x6.6x3.3 cm)
Wt: 7.1oz. (201g)
New Cornelia Mine, Ajo, Pima cty., Arizona
Thin crusts of pale blue ajoite crystals are scattered over the matrix of this specimen. On the top of the specimen, slight recesses allow the crystals to assume a little more of a three-dimensional appearance, although a loupe is needed to observe this. There is no damage to this specimen.
ajo-7 ($ 30.00)
New Cornelia Mine, Ajo, Pima cty., Arizona