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Formula: Ba4(Ti,Fe3+,Mg)4(O,OH)2[B2Si8O27]Clx
Cyclosilicate (ring silicate), borosilicate,
barium- and titanium- bearing
mineral, forms a series with taramellite
Crystal System: Orthorhombic
Specific gravity: 4.05 measured, 3.93 calculated
Hardness: 6
Colour: Dark brown to black
Common impurities: Mn,H2O
Environments
Contact metamorphic environments
Titantaramellite forms in the contact zones around granite,
quartz monzonite and
quartz diorite intrusives
(HOM).
It occurs as well-formed crystals, equidimensional to tabular. Associated minerals include
walstromite, verplanckite,
traskite, sanbornite,
quartz, pabstite,
muirite, macdonaldite,
fresnoite, benitoite and
bazirite
(Mindat). Titantaramellite changes to fresnoite at
960oC
(Webmin).
Localities
There are seven co-type localities:
Gun claim, Wilson Lake, Itsi Mountain, Watson Lake mining district, Yukon, Canada
The Madrelena mine, Tres Pozos, Baja California, Mexico
The Esquire No. 7 claim, Big Creek, Big Creek-Rush Creek Mining District, Fresno county, California, USA
The Esquire No. 1 claim, Rush Creek, Big Creek-Rush Creek Mining District, Fresno county, California, USA
The Trumbull Peak Ba-silicate deposit, Trumbull Peak, Clearing House, Clearing House Mining District, East
Belt, Mariposa county, California, USA
The Pacific Cement and Aggregate Company (Kalkar quarry), Santa Cruz, Santa Cruz county, California, USA
The Baumann prospect, Dumtah, Tulare county, California, USA
The Gun claim, Wilson Lake, Itsi Mountain, Watson Lake mining district, Yukon, Canada, is a type locality. In the
single specimen available, gillespite is a granular aggregate of anhedral
crystals mostly about 1 to 2 mm in size. Small rough grains of titantaramellite are embedded in the
gillespite
(AM.69.358-373).
The Madrelena mine, Tres Pozos, Baja California, Mexico, is a type locality. The
sanbornite-quartz rocks in some
places are only a few metres from the contact of metamorphic and plutonic rocks. The country rocks immediately
adjacent to the sanbornite bed are impure metasedimentary
quartzites, schists and
minor calc-silicates. La Madrelena mine is a small pit at
the western contact of one of the pendants (downward projections of country rock into an igneous intrusion) where
tonalite, quartzite,
tremolite schist and the
barium silicate rocks in which
sanbornite is the principal constituent are exposed.
Sanbornite is the principal mineral in all specimens, some crystals up
to 2 cm in size. Gillespite in elongated aggregates surrounded by
sanbornite is most conspicuous. In some places very small, but perfectly
euhedral, tabular crystals of titantaramellite are embedded in the leached
sanbornite
(AM.69.358-373).
Big Creek, Big Creek-Rush Creek Mining District, Fresno county, California, USA, is a type locality. Along Big Creek
there are numerous isolated occurrences of sanbornite rock. The host rocks
are mostly quartzite with some
calc-silicate rocks. In a small area near a
pellyite locality these rocks are free of
sanbornite and gillespite, and
consist principally of granular celsian up to several mm in size
enclosing titantaramellite. In some cases the titantaramellite encloses
quartz even though there is very little
quartz in the celsian matrix.
Salite and actinolite tend to
form bands in the celsian matrix or alongside the coarse
titantaramellite. Bazirite, identified by its blue-white
fluorescence under short wave UV, occurs in isolated crystals or small clusters 1 to 2 mm in size, and
gillespite occurs as ragged crystals with conspicuous cleavage up to
several inches in size in some quartz-rich rocks. Titantaramellite
has been found throughout the area
(AM.69.358-373). Other minerals associated with titantaramellite include
macdonaldite, walstromite,
fresnoite, verplanckite,
muirite, traskite,
benitoite and pabstite
(HOM).
Rush Creek, Big Creek-Rush Creek Mining District, Fresno county, California, USA, is a type locality. The area lies
within a body of metasediments completely surrounded by biotite
quartz diorite. The largest
bodies of sanbornite-quartz rock
occur at or close to the contacts of the metamorphic and plutonic rocks or entirely within the latter. Some of the
smaller bodies of quartz-sanbornite
rock are lenses entirely within the metamorphic rocks which are mostly
quartzite.
Taramellite in the barium-silicate rocks may be enclosed in
quartz or embedded in sanbornite.
Associated minerals include macdonaldite,
walstromite, fresnoite,
verplanckite,
muirite, krauskopfite and
traskite have been found here. In one specimen in which
walstromite is present in abundance, there are many small crystals of a
light green chlorite and
ripidolite, and a small amount of
pellyite was identified
(AM.69.358-373). Other associated minerals are benitoite,
pabstite and bazirite
(HOM).
The Trumbull Peak Ba-silicate deposit, Trumbull Peak, Clearing House, Clearing House Mining District, East
Belt, Mariposa county, California, USA, is a type locality. Sanbornite,
gillespite, celsian,
diopside, quartz,
pyrrhotite, witherite,
titantaramellite, pellyite and
alforsite have been found here. The principal
barium-silicates are sanbornite
and gillespite. Titantaramellite was present in minor amounts in
every specimen examined; it is found as small, mostly ragged, crystals; in places it forms small glomeroblasts which
may include pyrite
(AM.69.358-373).
The Victor claim, Picacho Peak, San Benito county, California, USA, is a type locality of titantaramellite
located in large slabs of metamorphic rocks surrounded by serpentine.
Barium-silicate minerals occur in veins in these rocks. The Benitoite Gem mine
is the type locality for the rare barium-silicate
benitoite. The small, hexagonal, platelets no more than a few millimeters
in size found at the Victor mine are markedly different from the blue
benitoite crystals of trigonal habit occurrimg at the Benitoite Gem mine.
The small colourless plates are most easily recognized by their pale bluish white fluorescence in short-wave UV. At the
Victor claim three other barium silicates,
joaquinite, fresnoite and
titantaramellite, have been identified among the vein minerals, together with
albite, apatite,
wollastonite and
adularia. Titantaramellite is by far the rarest of all these
minerals at the Victor claim, and it differs from titantaramellites from all the other type
localities in that it occurs as free-standing crystals rather than being embedded in
sanbornite or quartz
(AM.69.358-373).
The Pacific Cement and Aggregate Company (Kalkar), Santa Cruz, Santa Cruz county, California, USA, is a type locality
of titantaramellite. Here irregular beds of limestone were
converted into aggregates of quartz,
diopside, forsterite,
phlogopite, titanite,
tourmaline, chlorite,
arsenopyrite and pyrite.
The metamorphism of the limestone has been attributed to the effect
of nearby quartz diorite.
Barium-bearing minerals recognised at Kalkar are titantaramellite,
celsian, pabstite and
witherite. The tin-bearing minerals
are stannite, franckeite,
cassiterite and pabstite.
It has been estimated that the temperature of mineral formation ranged from above 600oC to below
400o. Titantaramellite and pabstite are limited in their
occurrence to a small area of the deposit. Titantaramellite has not been found in place, but only in piles of
rock on the quarry floor.
The titantaramellite appears in crystals up to 3 inches long, anhedral and mostly intergrown with
tremolite so that they often appear fibrous as does the
titantaramellite. Nearly pure diopside is more abundant than
tremolite but is not intergrown with titantaramellite. Specimens
containing titantaramellite invariably also contain pabstite, and
meneghinite and arsenopyrite
are common associates
(AM.69.358-373). Other associated minerals include celsian,
galena, cassiterite and
quartz
(HOM).
The Baumann prospect, Dumtah, Tulane county, California, USA, is a type locality of titantaramellite. It lies
in a body of metasedimentary rocks, mainly mica
schist and impure
quartzite. The barium minerals
occur in a zone in quartzite of a pale yellowish grey rock which
consists of sanbornite and
witherite with quartz.
Baryte occurs as cream-coloured masses up to several inches thick.
Titantaramellite and fresnoite have been found in samples from the
deposit. Titantaramellite was found in each of the five specimens examined. Thin veins of
quartz and krauskopfite were
found in two specimens. Witherite is a major constituent of several of the
specimens, but celsian, omnipresent in other
barium silicate deposits and a major constituent in places, is inconspicuous
or lacking here
(AM.69.358-373).
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