670 MINERAL RESOURCES; 1913—PART II.
purposes.
This is due to inferior color of the crystals, excessive fracturing, or
discoloration by iron rust. The amazon stone and other microline occurs
in stout crystals with the characteristic prominent cleavage of that
mineral. The crystals range from small size to several inches in
diameter and project from the walls of the cavities with crystals of
smoky quartz, biotite, and the other minerals of the pockets. In some
cases clusters of fine amazon stone crystals, with or without other
minerals, can be removed from the prospects for cabinet specimens. Most
of the pockets contain grayish microcline crystals as well as those of
green color.
The
amazon stone occurs in various shades of bluish green, some of which
are very bright. Occasional specimens of nearly pure pale blue are
found. Most of the crystals show color variations, the best color
commonly lying near the outside of the crystals. Such crystals may have
bright bluish-green exteriors with successively paler colors toward the
middle, either in layers or by gradual change. The middle of these
crystals is generally gray or only pale bluish green. The out-side
shell of good color may range from a small fraction of an inch to an
inch in thickness in large crystals. This color variation must be taken
into consideration in the choice of cutting material, as occasions
large waste.
The
amazon stone can be cut in a variety of shapes for gem pur-poses, such
as stones for brooches, scarfpins, pendants, and beads for necklaces.
The bright colors are pleasing and blend well with gold mountings. Some
of the cut stones exhibit a silvery sheen in certain lights from partly
developed cleavage planes. In considering the class of semiprecious and
imitation stones sold to the tourists in Colorado each year, it seems
that the possibilities of beautiful amazon stone from the Pikes Peak
region are almost neglected. A quantity of amazon stone is sold in the
rough in the form of crystals and bright-colored specimens to the
tourist trade and many fine crystals are sold by mineral dealers for
cabinet specimens elsewhere; but the sale of cut gems could be
increased by displaying tastefully cut stones of good color.
SUNSTONE. CALIFORNIA.
