TANTALITE
Specimen tnt-4

Dims: 3.6" x 2.0" x 1.6" (9.1 x 5.1 x 4.1 cm)

Wt: 3.59 oz. (101.9

Cruzeiro Mine, Minas Gerais, Brazil

A single Tantalite crystal is nestled in a matrix made up of intergrown clusters of crystalline lepidolite. It has dimensions of 1.0 x 0.6 x 0.4" (2.5 x 1.5 x 1.0 cm), and is in excellent condition, showing almost no damage. Though somewhat disjointed due to its intergrowth with the lepidolite, the crystal's form is nonetheless excellent, with well-defined edges and clean, though often striated faces that show a submetallic luster. One can easily see that it is double-terminated. It is opaque and has a black color, but shows colorful iridescence at certain angles. Adjacent to the Tantalite is a prismatic elbaite crystal, whose form is also somewhat disjointed. It shows considerable damage in the form of breakage planes; one of these

Dims: 1.3" x 0.8" x 0.8" (3.3 x 2.0 x 2.0 cm)

Wt: 16.2 g

Quixaba Mine, Frei Martinho, Paraiba, Brazil

At least 2 Tantalite crystals are partially embedded in the quartz matrix of this specimen. They are of the manganese-rich variety of Tantalite that is known simply as Manganotantalite. Only one of these crystals appears to be complete; it is not fully exposed, and what is visible has dimensions of 0.3 x 0.2 x 0.1" (8 x 5 x 3 mm). It shows reasonably good orthorhombic prismatic form, and has a deep red coloration with a hint of brown and a bright, pearly luster. Besides the quartz, there is a small amount of muscovite at the crystal's base.

Dims: 1.5" x 0.8" x 0.5" (3.8 x 2.0 x 1.3 cm)

Wt: 14.9 g

Quixaba Mine, Frei Martinho, Paraiba, Brazil

This small thumbnail specimen consists of at least 4 Manganotantalite crystals that are embedded in a pegmatite base. These crystals are in moderately good condition, as the largest one is obviously damaged and missing part of its termination. This largest crystal has visible dimensions of 0.8 x 0.3 x 0.1" (2.0 x 0.8 x 0.3 cm), and like the others, shows a warped but definite orthorhombic prismatic form and a pearly luster. It has a brownish-red coloration and would likely be transparent if it was not so intensely internally-fractured; it is translucent at the least, though. Some of the crystals seem to show good form, but are almost completely covered by the base rock, which protected them. As the base rock does not react to concentrated HCl, I am rather certain that it consists almost entirely of a feldspar.

Dims: 1.3" x 1.3" x 1.0" (3.3 x 3.3 x 2.5 cm)

Wt: 1.13 oz. (32.1 g)

Quixaba Mine, Frei Martinho, Paraiba, Brazil

This small specimen consists of an incomplete Manganotantalite crystal that is partly embedded in a massive quartz matrix. The "crystal" has dimensions of 0.5 x 0.4 x 0.2" (1.3 x 1.0 x 0.5 cm) and is broken on 2 ends; however, one of these ends is partly embedded in the host rock, so maybe some of its termination has been left intact. The Manganotantalite has a deep red-black coloration with a hint of brown and a bright, adamantine luster that shows some almost metallic highlights. It appears to be essentially opaque. There is also some pale green muscovite present on the specimen that has a few odd tendencies to it; it appears to have filled random hollows in the host rock, and apart from its flaky, micaceous consistency, shows no actual crystalline form!

Dims: 2.6 x 1.8 x 1.0" (6.6 x 4.7 x 2.5 cm)

Wt: 3.5 oz. (99 g)

Mount Kharitha, Kala Darrah Pech, Kunar Province, Pakistan

A single partial Tantalite crystal is partly embedded in the pegmatite host of this hand specimen. It has visible dimensions of 1.3 x 1.1 x 0.6" (3.2 x 2.9 x 1.5 cm) and is in merely fair condition, as it shows a large amount of relatively fresh damage. However, some slight healing may have occurred prior to mining, as I keep seeing what appear to be crystalline striations on some of the broken faces. Where intact, it shows good orthorhombic prismatic form, though old, healed-over damage has warped its form a bit. It has a brown-black color and a bright, vitreous luster, but where it has been weathered, the color is a paler, dark brown and the luster is dull. The pegmatite base also contains a few veins of pale smoky quartz.

Dims: 2.4 x 1.6 x 1.4" (6.1 x 4.1 x 3.5 cm)

Wt: 4.6 oz. (129 g)

Mount Kharitha, Kala Darrah Pech, Kunar Province, Afghanistan

A cluster of heavily-intergrown Tantalite prisms is partly embedded in the pegmatite base of this hand specimen. The crystals are in fair condition, as the largest ones are heavily cleaved and incomplete. These large crystals tend to measure about 0.5" (1.3 cm) in diameter- the rest are considerably smaller and are quite intergrown with the two aforementioned crystals. All show excellent orthorhombic form, a brown-black color and a dull, almost submetallic luster where intact. Where they are damaged, they show a very pronounced and deep red-brown coloration and a pearly luster.