MOLYBDENITE, M-450. Australia. 3/4 to 1-1/2 inch xls.
pure, no matrix or contaminate. Average 6 to 12 grams per xl., sold
by weight or individual sample.
Dakota. Nearly white cleavage masses. SL Check.
MONTICELLITE, M-460. California.
Light olive green, compact, fine grained crystalline
South Dakota. Gray clay masses - gravel size
lumps. Because it decrepitates in the atmosphere, it is
packaged in individual plastic bags in sizes equivalent to
listed sizes. Check for availability. (For other clay, see fire clay under
MUSCOVITE, M-470.South Dakota.
Silvery, vitreous mica cleavage books around 1" and
1/4 to 1/2 inch thick.
Canada. Light gray. Greasy luster.
M-485. Canada. White
cleavages of plagioclase that can show twinning striae. Check for
OLIVINE, M-490 North Carolina, Light
to medium grass green or olive green, sugary crystalline
Granular to coarse crystalline, grayish green,
some interrupted cleavage faces. Near Forsterite
end of series. Check.
OLIVINE, Peridot. Crystalline on basalt. 2"
and larger only. AZ.
California. Light gray, red, brown and
green, etc. Pearly to resinous common
OPAL (DIATOMITE, DIATOMACEOUS
M-500. California or Nevada. White
to light grayish, friable, earthy masses.
M- 505. Sold by weight. Nevada.
Pure yellow crystals with minor surface alteration. Xls sizes 2cm to almost 6cm.
M-505A. Nevada. Massive bright yellow with associated realgar.
M-507. Nevada & Colorado. Excellent crystal samples
of this mineral. Beige to pink to brown crystals averaging 1 inch in
ORTHOCLASE - For other "Orthoclase" or Potassium feldspar, or
K-Spar, see Microcline.
PHLOGOPITE MICA, M-510.
Canada. Bronze to black cleavage book. SL
M-515. California. About
8 - 10 crystals about 1/4 inch (orthorhombic, translucent, gray)
in a plastic envelope.
PLAGIOCLASE, see under ALBITE, ANDESINE,
ANORTHITE, LABRADORITE, OLIGOCLASE.
Yellow-brown, earthy lumps and powder in
1 ounce bag. Check.
M-525. Utah. Colorless
to buff groups of 2-30 mm octahedral
crystals. Around 3/4 inch to 1 inch pieces
available. Check. SL
Colorless, glassy, acicular crystalline
masses. Some with radial structure. SL