|
Click on a
letter above to view the list of gems. |
|
| Chemistry:
NaCaB5O6(OH)6·5(H2O) | Discovered
in 1850;
IMA
status: Valid (pre-IMA; Grandfathered). Ulexite is
named in honor
of George Ludwig Ulex (1811–1883), German chemist who
obtained the first reliable analysis of the mineral. |
|
Classification
|
|
|
Mineral
Classification: |
Borates |
Strunz 8th
Ed. ID:
|
5/H.14-10 |
Nickel-Strunz 10th
Ed. ID:
|
6.EA.25 |
|
6 : BORATES E : Pentaborates A : Neso-pentaborates
|
|
|
Crystal
Data
|
|
|
Crystallography:
|
Triclinic - Pinacoidal |
Crystal
Habit:
|
Rare
as measurable crystals, which may have many forms; typically
elongated to acicular, to 5 cm, then forming fibrous
cottonball-like masses; in compact parallel fibrous
veins, and radiating and compact nodular groups.
|
Twinning:
|
Polysynthetic
|
|
|
Physical
Properties
|
|
|
Cleavage: |
[010] Perfect, [110] Perfect
|
Fracture: |
Irregular,
Uneven across fiber groups
|
Tenacity:
|
Brittle
|
Moh's
Hardness: |
2.5
|
Density:
|
1.95 - 1.96 (g/cm3) |
Luminescence:
|
None |
Radioactivity:
|
Not
Radioactive
|
|
|
Optical
Properties
|
|
|
Color: |
Colorless,
White |
Transparency: |
Transparent,
Translucent, Opaque |
Luster: |
Vitreous,
Silky, or
Satiny in fibrous aggregates |
Refractive
Index: |
1.491 - 1.520 Biaxial
( + ) |
Birefringence: |
0.028 |
Dispersion: |
None
|
Pleochroism: |
None
|
|
|
Occurances
|
|
|
Geological
Setting: |
Typically
in playa and salt-marsh deposits in arid regions and
bedded sedimentary deposits formed from these, the boron
supplied from surrounding hot springs. Some occurrences
contain upwards of one billion tons of Ulexite. |
Common
Associations: |
Borax,
Calcite, Colemanite, Glauberite, Gypsum, Halite, Hydroboracite,
Meyerhofferite, Mirabilite, Probertite, Trona |
Type
Locality: |
Iquique Province, Tarapacá Region, Chile |
Year
Discovered: |
1850 |
View
mineral photos: |
Ulexite
Mineral Photos and Locations |
|
|
More
Information
|
|
|
|
Mindat.org Webmineral.com |
|
|
Ulexite
is a rare borate mineral very similar to Hydroboracite.
They
both commonly form as silky, fibrous crystal clusters
and are not easy to distinguish. Ulexite
is an interesting mineral in that is very fibrous and
the fibers are transparent along their length and packed
tightly together so that they act like an array of parallel
glass fibers. If the material is polished perpendicular
to the fiber direction, a piece of Ulexite will transmit
an image from the bottom of the piece to the top. This
optiacal phenomenon is the reason Ulexite has been nicknamed
TV stone. Ulexite pieces are typically cut and
polished only on the ends as a novelty item. Cats Eye
cabochons are also available. Faceted gems are extremely
rare because the material is usually too fibrous to facet.
The
most notable occurances of Ulexite are Bigadiç Mine, Bigadiç, Balikesir Province, Marmara
Region, Turkey; Boron Pit, U.S. Borax Mine, Boron, Kramer District, Kern
County, California, USA; Anniversary Mine (Callville Wash), White Basin, Muddy
Mountains District, Clark County, Nevada, USA.
|
Ulexite
gems for sale:
We
have not photographed our Ulexite gems yet. Please check
back soon!
|
|