THE MINERAL BRAZILIANITE

  • Chemistry: NaAl3(PO4)2(OH)4, Sodium Aluminum Phosphate Hydroxide.
  • Class: Phosphates
  • Uses: As a gemstone and as mineral specimens
  • Specimens
Brazilianite is an unusual gemstone mineral. It is one of the only phosphate minerals to be used as a serious gemstone. Although the phosphate mineral apatite is cut into gems it is not considered as precious as brazilianite. Of course brazilianite is relatively new to the mineral markets and is still not well known to everybody.

It has a fair luster and interesting color, a yellow to greenish yellow. It may look a little like yellow topaz but brazilianite tends to be more green. Although not as hard as most other gemstones, it is one of the hardest phosphate minerals.

Brazilianite is found in phosphate rich pegmatites. The igneous pegmatites are rather unusual for their phosphate content. Brazilianite was discovered in Brazil (hence the name) and was later discovered in New Hampshire at the Palermo Mine. The discovery at the Palermo Mine surprised many geologists who had studied the minerals there in detail and yet had "missed" this new mineral.

PHYSICAL CHARACTERISTICS:

  • Color is yellow to greenish yellow and colorless.
  • Luster is vitreous.
  • Transparency: Crystals are transparent to translucent.
  • Crystal System: Monoclinic; 2/m
  • Crystal Habits include complex short prismatic and wedge shaped crystals that seem to lack any symmetry. Crystals are very common, and massive examples are almost unknown.
  • Cleavage is perfect in one direction.
  • Fracture is conchoidal.
  • Hardness is 5.5
  • Specific Gravity is approximately 3.0 (average for translucent minerals)
  • Streak is white.
  • Other Characteristics: Crystals are striated and the index of refraction is 1.60 - 1.62
  • Associated Minerals are quartz, feldspars, muscovite and primary and secondary phosphates associated with phosphate rich pegmatites.
  • Notable Occurrences include Conselheiro Pena and other mines in Minas Gerias, Brazil and Smith Mine, Newport, New Hampshire.
  • Best Field Indicators are color, crystal habits, low density and cleavage.
BRAZILIANITE specimens:
(hover for more info)
BRAZILIANITE specimen bra-1
$ 52.50
Dims: 1.75" x 1.5" x 1.25"(4.4 x 3.8 x 3.2 cm)
Wt: 1.20 oz.(34.1 g)
Corrego Frio, Minas Gerais, Brazil
This specimen is made up almost entirely of Brazilianite, a little-known phosphate gemstone. Several small crystals and portions of large crystals make up the mass, along with a small portion of muscovite books. The Brazilianite has a pale greenish-yellow coloration and a vitreous to pearly luster. The material is translucent but very cloudy, with veil-like inclusions and many internal fractures. The crystals are four-sided with a rhombic cross-section and asymmetrical pinacoidal termination. The largest complete crystal measures 1/2"(1.3 cm) in length and is missing 2 of its 4 termination faces. Other crystals may be found among the muscovite books, which help to shelter them from breakage. I don't think that many people have one of these in their collections.
no photo
bra-1 ($ 52.50)
Corrego Frio, Minas Gerais, Brazil
BRAZILIANITE specimen bra-2
$ 48.00
Dims: 0.6" x 1.0" x 0.4"(1.5 x 2.5 x 1.0 cm)
Wt: 4.9 g w/ specimen box
Governador Valadares, Minas Gerais, Brazil
The form of the two Brazilianite crystals in this specimen is quite unusual. They constitute the entire specimen- one measures about 1"(2.5 cm) in length, and the other about 3/4"(1.9 cm). They have a pale yellow color with a hint of green and are transparent but heavily internally-fractured. They have a pearly to vitreous luster and occur in pseudotetragonal prismatic crystals with steep angled terminations. However, the two temination faces on each crystal have bizarre "hopper"-like formations that resemble "skeletal crystals". I don't know if this is a common occurrence for this mineral. Also, the smaller of the two crystals is double-terminated, although the second termination is missing its tip. The specimen is glued into a plastic specimen box. It is a piece that I want to spend "too much time" studying.
no photo
bra-2 ($ 48.00)
Governador Valadares, Minas Gerais, Brazil
BRAZILIANITE specimen bra-3
$ 55.00
Dims: 1.9" x 1.9" x 1.3" (4.8 x 4.8 x 3.3 cm)
Wt: 1.67 oz. (47.5 g)
Linopolis, Divinodas Laranjeires, Minas Gerais, Brazil
This specimen shows a lot of damage, as most of the Brazilianite crystals therein are either heavily intergrown, broken, or both. There are several, however that are intact and undamaged, though they tend to be quite small. The largest discernable crystal has dimensions of 0.6 x 0.4 x 0.2" (1.5 x 1.0 x 0.5 cm); it is missing a substantial part of its termination, but its monoclinic prismatic form is evident. All of these crystals show a pale yellow color that is subtly tinged with green and have a bright, vitreous luster. They are transparent and moderately clear, though even the intact crystals show noticeable internal fracturing. Along with the tangle of Brazilianites are a small piece of what looks like a white feldspar, and an intact "book" of muscovite of impressive quality; it shows no damage, and though its shape is rounded and warped in some spots, it is quite attractive. There is no host rock present.
no photo
bra-3 ($ 55.00)
Linopolis, Divinodas Laranjeires, Minas Gerais, Brazil
BRAZILIANITE specimen bra-4
$ 60.00
Dims: 1.0 x 1.0 x 0.6" (2.5 x 2.5 x 1.6 cm)
Wt: 0.2 oz. (7 g)
Mendes Pimental, Minas Gerais, Brazil
A cluster of four separate and distinct Brazilianite crystals rests on the albite base of this thumbnail piece. Only two of these crystals are intact and complete, and the largest has dimensions of 1.0 x 0.5 x 0.3" (2.5 x 1.3 x 0.8 cm); the smaller one is about 75% of the size of the larger. Both are in excellent condition, showing no appreciable damage, and both have excellent monoclinic bladed form. Their color is the standard yellow-green and their luster is vitreous, and both are transparent and dimly to moderately clear due to intense internal fracturing.
no photo
bra-4 ($ 60.00)
Mendes Pimental, Minas Gerais, Brazil
BRAZILIANITE specimen bra-5
$ 29.00
Dims: 1.0 x 0.9 x 0.6" (2.6 x 2.2 x 1.5 cm)
Wt: 0.2 oz. (5 g)
Mendes Pimental, Minas Gerais, Brazil
This thumbnail piece consists of a cluster of at least 6 separate Brazilianite crystals that rest on an albite base. The crystals are generally in good condition, though two of them are broken and incomplete. The largest intact crystal measures 0.7" (1.9 cm) and, like all the others, has excellent monoclinic bladed form. All likewise have the standard green-yellow color and vitreous luster and are transparent and moderately clear due to internal fracturing.
no photo
bra-5 ($ 29.00)
Mendes Pimental, Minas Gerais, Brazil
BRAZILIANITE specimen bra-6
$ 38.00
Dims: 1.8x1.2x0.7" (4.5x3.0x1.7 cm)
Wt: 0.7 oz. (20.2g)
Linopolis, Minas Gerais, Brazil
This arrowhead shaped specimen of brazilianite is a greenish-yellow color, typical for the species. It is transparent, but a myriad of internal fractures makes it impossible to see more than a few millimeters into the crystal. The front crystal faces are natural and clean, and at first I thought that the rear faces were formed by cleavage or fracture, but after close examination, I believe that the faces are natural growth faces, even though they are rough.
no photo
bra-6 ($ 38.00)
Linopolis, Minas Gerais, Brazil
 

Copyright ©1995-2023 by Amethyst Galleries, Inc.