ULEXITE
Specimen ule-4

Dims: 2.8" x 2.1" x 1.6" (7.1 x 5.3 x 4.1 cm)

Wt: 4.33 oz. (122.7 g)

White Monster Mine, Death Valley, Calfornia, U.S.A.

This is the first Ulexite specimen that I have seen with a fibrous, radiating habit. It is still compact, but it does not occur in the highly compact, columnar "TV Rock" formation that is most well-known for this mineral. The cluster is incomplete and shows substantial damage in the form of crushed and incomplete crystals, but still shows a definite radial habit. The crystals may be individually colorless and transparent, but when compacted together show a bright, white coloration and almost complete opacity. They measure an average of just under 1" (2.5 cm) in length. The cluster is attached to a host of what I think is either trona or massive colemanite- it is difficult to tell.

Dims: 4.9 x 3.7 x 2.6" (12.5 x 9.4 x 6.6 cm)

Wt: 1 lb., 4.0 oz. (565 g)

Boron, Kern County, California, U.S.A.

This large cabinet specimen consists of a chunk of compact, fibrous Ulexite. It shows some fresh damage and considerable weathering, but is still in good condition. Individual crystals are impossible to study, but its habit is standard for the specie. It has a milky-white color and a silky luster due to its fibrosity, and is essentially opaque under normal light. A few other borate minerals may be present, but if so, they are difficult to isolate.

Dims: 7.9 x 4.1 x 2.9" (20.1 x 10.3 x 7.5 cm)

Wt: 3 lbs., 1.6 oz. (1.046 kg)

Boron, Kern County, California, U.S.A.

This display piece consists of a large section of compact, columnar Ulexite. As is usual with this mineral, no definite crystals are present, but its crystalline tendencies are obvious. It has a grayish, milky-white color and a dull, silky luster along its length, and is dimly translucent. One small area shows brighter white color and fibrous, radiating tendencies. Even in its rough state, there are one or two areas that exhibit its inherent "fiber optic" properties. Only a small amount of a dull, gray-black host material is present.

Dims:6.4x2.5x2.2" (16.3x6.4x5.6 cm)

Wt: 21.1oz. (599g)

Kern cty., California

This specimen is a columnar crystal fragment of ulexite on matrix. The ulexite crystal itself measures over 4.0" (10.1cm). It is unusual to find good matrix specimens of this mineral. The crystal is white, and very translucent on the edges where it is thinnest. This specimen shows some cleavages where it was broken away from the host material.