Brazilianite: A Pegmatite Phosphate Named for Its Country

Short answer: brazilianite is a sodium aluminum phosphate, NaAl3(PO4)2(OH)4, that grows as glassy yellow to yellow-green crystals in the pocket zones of granite pegmatites. It was discovered in Minas Gerais in 1944 and Brazil remains the only important source of large crystals. Collectors price it on color, transparency, sharp terminations and matrix, and cut stones over 5 carats are scarce. It is Mohs 5.5, SG about 2.98, and loses color when heated.

What is brazilianite, mineralogically?

Brazilianite is a phosphate, not a silicate, which puts it in the same broad chemical family as apatite and turquoise rather than with the beryls and tourmalines it grows beside. Webmineral's calculated composition is sodium 6.35%, aluminum 22.37% and phosphorus 17.12% by weight, and it gives a specific gravity of 2.98 (webmineral). Dana's system files it under anhydrous phosphates containing hydroxyl (class 41.05.07.01); in Strunz it is 08.BK.05.

The International Gem Society lists every number above except the composition (IGS). The absence of fluorescence and the weak pleochroism are useful negatives: brazilianite looks lively in daylight, but it does very little under a UV lamp or a dichroscope.

How and when was brazilianite discovered?

Brazilianite is a young species by collector standards. The IGS dates its discovery in Brazil to 1944, and webmineral records it as a valid species with a 1945 date, named after its first discovery in Brazil. The type locality is the Córrego Frio mine at Linópolis, in Divino das Laranjeiras in the Doce valley of Minas Gerais. When crystallographers Gatehouse and Miskin published its crystal structure in Acta Crystallographica in 1974, the crystal they used came from the same Córrego Frio pegmatite.

The name carries a practical consequence for buyers. Because the mineral was named for the country and the country still supplies most of it, "Brazilianite, Minas Gerais, Brazil" on a label is expected rather than impressive. The mine name, such as Córrego Frio or Telírio, is what adds value. For the wider picture of the state's pegmatite belt, see the Brazil origin guide.

How does brazilianite form in pegmatites?

Brazilianite is a late, low-temperature mineral of granite pegmatites. The IGS describes its occurrence as a hydrothermal mineral in pegmatitic cavities.

Geology.com explains why pegmatites grow crystals this large. A crystallizing magma holds dissolved water and other volatiles such as fluorine and carbon dioxide. Because early-forming minerals do not take up the water, its concentration keeps rising until pockets of superheated, ion-rich water separate from the melt, and ions moving through that water build crystals quickly (Geology.com). By definition, a pegmatite is made almost entirely of crystals at least one centimeter across. Phosphorus is one of the elements left over at the end of that process, and where it meets sodium and aluminum in an open pocket, brazilianite can crystallize on the walls.

That history shows in specimens. Brazilianite usually sits on or among the last pocket minerals:

• Albite, often as the platy white variety cleavelandite. Minerals.net records enormous cleavelandite crystals from several areas of Minas Gerais, especially the Doce and Jequitinhonha valleys (Minerals.net, Albite).
• Muscovite, the common mica, in silvery books and flakes. Geology.com notes it is the most common mineral of the mica family and cleaves into thin transparent sheets (Geology.com, Muscovite).
• Quartz, sometimes as a vug lining around the brazilianite.

The general mechanics of these rocks, and why they also yield tourmaline and aquamarine, are covered in the pegmatite guide.

Where is brazilianite found besides Minas Gerais?

The IGS names Conselheira Pena in Minas Gerais as the principal source of gem material in crystals up to large sizes, with crystals from Brazil reaching 12 x 8 cm. Outside Brazil, two localities matter to collectors:

• Palermo Mine, New Hampshire, USA: sharp yellow crystals, usually small. The IGS notes a vug specimen whose brazilianites reach 1.1 cm, which it calls very large for the locality.
• Rapid Creek, Yukon, Canada: fine but small crystals.

In practice, anything over a couple of centimeters is Brazilian, and a well-documented North American piece trades on locality rather than size.

How do you recognize brazilianite and tell it from apatite?

Yellow-green transparent crystals in pegmatite pockets could be several things, and apatite is the most frequent confusion because it is also a phosphate and also occurs in the same Minas Gerais district. Minerals.net lists apatite from the Sapo mine in Conselheiro Pena among the state's outstanding occurrences (Minerals.net, Apatite).

Shape is the quickest field check: a six-sided prism with flat terminations points to apatite, while a wedge- or spear-shaped crystal points to brazilianite. Weight is the most reliable one. The IGS gives apatite crystals a specific gravity of 3.10 to 3.35 (IGS, Apatite), so with a careful hydrostatic weighing, brazilianite always comes out lighter. Massive blue apatite, the common decor material, does not resemble brazilianite at all.

Is brazilianite heat-sensitive, and how should you care for it?

Yes, and this is its most important care rule. The IGS reports that heating brazilianite to 140 °C (284 °F) can cause color loss, and that heating to 300 °C (572 °F) turns it colorless. A jeweler's torch reaches those temperatures easily, so a ring or pendant should come out of its setting before any repair. Do not leave specimens in a hot car or under strong display lamps.

Cleaning follows from its cleavage and its pocket matrix. Use a soft brush, mild detergent and lukewarm water, and avoid steam and ultrasonic cleaners. Muscovite flakes on a matrix piece lift off when scrubbed, so brush around them.

What drives brazilianite prices?

Brazilianite is a collector species with a thin market, so prices vary more than for common minerals. The factors that move them:

1. Transparency and color. Gemmy yellow-green crystals with even color sit at the top; cloudy or fractured crystals are priced as study pieces.
2. Terminations. Sharp, undamaged wedge terminations matter more than length. Chips on a termination cut value sharply.
3. Matrix. Crystals on contrasting white albite with muscovite display better and usually cost more than loose crystals of the same size.
4. Size. Crystals range up to 12 x 8 cm, but most specimens are thumbnail to small cabinet size.
5. Cut stones. The IGS says most cut gems range from one to ten carats, cut stones over five carats are scarce, and clean faceted gems over 15 carats are a great rarity. For scale, it lists Smithsonian stones of 41.9 and 17.0 carats.
6. Locality. A named Brazilian mine or a documented Palermo or Rapid Creek label adds value over a generic "Brazil."

Expect high prices per gram compared with common minerals: a small, sharp brazilianite costs far more than a decor stone of many times its weight. It does not usually reach the price levels of the pieces in the most valuable crystals guide, but it belongs to the same collector-driven market.

Buying brazilianite: what to look for

• Ask for the weight and dimensions and judge price against both.
• Check terminations under magnification in the photos; ask whether any crystal is reattached.
• Look for the matrix minerals (albite, muscovite, quartz) as a sign of a genuine pocket specimen.
• Confirm the species. For a high-value piece, a seller should be able to say how it was identified; apatite is the usual mix-up.
• Plan the display away from heat sources.

From what we stock:

• Brazilianite Cluster: brazilianite with muscovite and albite from Minas Gerais, about 2 x 1 x 1 inches and 17 g, a compact example of the classic pocket association.
• Brazilianite Specimen: from Minas Gerais, about 1.5 inches and 27 g, a heavier piece for a collector who wants more crystal mass.
• Watermelon Tourmaline on Albite Matrix 51g: a Brazilian pegmatite companion piece that shows the same white albite host.
• Blue Apatite: freeforms about 2.25 inches long; a reference for how apatite, the other common phosphate, looks in its massive form.

Frequently asked questions

Is brazilianite rare?

It is uncommon. Brazilianite forms only in the late pocket stage of certain granite pegmatites, and nearly all large crystals come from Minas Gerais. Small specimens are available to collectors, but clean faceted stones over 15 carats are a great rarity.

Is brazilianite good for jewelry?

It can be worn with care. At Mohs 5.5 with good cleavage it scratches and chips more easily than quartz, so pendants and earrings suit it better than rings. Its heat sensitivity means stones must be removed from settings before repairs.

Why is it called brazilianite?

It was named after Brazil, where it was first discovered in 1944. The type locality is the Córrego Frio mine at Linópolis in the Doce valley of Minas Gerais, and Brazil remains its principal source.

How can you tell brazilianite from apatite?

Look at crystal shape and weight. Apatite forms six-sided hexagonal prisms and has a specific gravity above 3.1, while brazilianite forms monoclinic wedge or spear shapes and has a specific gravity of about 2.98. Apatite from some localities also fluoresces; brazilianite does not.

Does brazilianite fade?

Heat is the danger. Heating to 140 °C can reduce its color and 300 °C turns it colorless. Keep specimens away from hot cars, heaters and hot display lamps, and never expose a brazilianite to a jeweler's torch.

Sources

• International Gem Society, Brazilianite Value, Price, and Jewelry Information: https://www.gemsociety.org/article/brazilianite-jewelry-gemstone-information/
• webmineral, Brazilianite Mineral Data: http://webmineral.com/data/Brazilianite.shtml
• Geology.com, Pegmatite: https://geology.com/rocks/pegmatite.shtml
• Minerals.net, Albite: https://www.minerals.net/mineral/albite.aspx
• Geology.com, Muscovite: https://geology.com/minerals/muscovite.shtml
• Minerals.net, Apatite: https://www.minerals.net/mineral/apatite.aspx
• International Gem Society, Apatite Value, Price, and Jewelry Information: https://www.gemsociety.org/article/apatite-jewelry-and-gemstone-information/