Images
Formula: Sr2B11O16(OH)5.H2O
Hydrated pentaborate,
strontium-bearing mineral
Crystal System: Monoclinic
Specific gravity: 2.58 to 2.69 measured, 2.59 calculated
Hardness: 2
Streak: White
Colour: Colourless, white
Environments
There are three known polytypes of veatchite, A, 1M and 2M
Veatchite is uncommon in evaporite borate deposits formed by volcanic
activity
(HOM).
Localities
At the Emet Borate deposit, Emet District, Kütahya Province, Turkey, the borate
deposits have been formed in the sediments of playa lakes. Borate formations are
interbedded with clays, marls and
volcanic tuffs, and are related to volcanic activity.
The principal mineral of the Emet borate deposits is
colemanite.
In the Killik mine, the colemanite is associated with
hydroboracite, ulexite,
veatchite-A, tunellite,
meyerhofferite, cahnite,
realgar, orpiment,
calcite and aragonite.
In the Hisarcrk area colemanite is associated with
hydroboracite, ulexite,
teruggite, cahnite,
veatchite-A, celestine, gypsum,
native sulphur, realgar,
orpiment and calcite.
Veatchite-A occurs in cauliflower-shaped nodules ranging from 0.5 to 1O cm in diameter. Nodules are rarely composed
of countless minute euhedral crystals, but are commonly compact with euhedral crystals on the surface forming radiating
aggregates. Realgar, orpiment and
montmorillonite occur among the crystals and in small veinlets. The
nodules are found in clays, on
colemanite nodules and on
hydroboracite occurrences.
Replacement of colemanite by veatchite-A is seen in thin sections and
also on the macroscopic samples. The formation of veatchite-A is later than
hydroboracite and colemanite
where hydroboracite is an alteration product of
colemanite. Veatchite-A is not associated with
tunellite. Specific gravity is 2.77 calculated and 2.73 measured.
Veatchite-A crystals are platy and generally composed of stacked cleavage plates, probably containing entrapped
air
(AM 64.362-366).
Veatchite from the Emet Borate Deposit -
Image
At the type locality, the Lang Mine, Tick Canyon Borate deposit, Tick Canyon, Lang, Los Angeles County, California, USA,
the exact mode of occurrence of veatchite is not known. Although the specimens show veatchite veins cutting
limestone and howlite, they
were found as part of a small boulder lying in the wash, and none of the material has yet (in 1938) been found in place
(AM 23.6.409-411).
The veatchite occurs as silky fibrous crystals encrusting colemanite
and clay on massive howlite
(AM 41.690).
Veatchite from the Lang Mine - Image
Back to Minerals