-
cleavage is mica,
which cleaves in a
single direction along the
basal pinacoid,
making the
layers seem like
pages in a book. In fact,
mineralogists often...
-
intersect at
about 120
degrees in a three-fold
direction of the
basal pinacoid.
Black star
sapphire is
found in Thailand, Cambodia, Tanzania, Australia...
-
tabular to
prismatic crystals with an
obvious pinacoid termination. It has four
prism faces and two
pinacoid faces to form a
pseudohexagonal crystal. Although...
- (Cu,Zn)2Zn[(As,Sb)O4](OH)3
Crystal system Trigonal Crystal class Basal Pinacoid Space group P3 Unit cell a=8.201(1), c=7.315(1)Å
Identification Color Emerald...
- are
generally tabular in
habit owing to the
predominance of the
basal pinacoid;
numerous smooth bright faces are
often developed on the
edges and corners...
-
Predominant crystal faces (prism - prismatic,
pyramid -
pyramidal and
pinacoid - platy).
Crystal forms (cubic, octahedral, dodecahedral). Aggregation...
- faces, also as
tapering six-sided
pyramids that can be
truncated by the
pinacoids. Also m****ive,
lamellar and in
small grains in
sulfide ore
bodies Cleavage...
- plates, or
short prisms,
showing hexagonal dipyramids,
pyramids and
basal pinacoid. {1010}, {1011} and {0001} dominant. May also be
tabular or rhombohedral...
- from pale to
green Crystal habit Tabular rectangular crystals with two
pinacoid faces;
foliated or
micaceous aggregates Twinning Merohedrally twinned Cleavage...
- a
nearly square cross-section
formed by the
equal development of two
pinacoids. The
crystals are
about 1–3 μm
thick and 50–80 μm long,
arranged in loosely...
