semi precious stones
AGATE
Agates are made up of silicon dioxide, which is deposited in nodular masses in volcanic lavas. Colors are due to various minerals that stain the mass, usually in colorful bands that distinguish agate from other kinds of microcrystaline quartz, such as chalcedony Agates are usually brown, but the colors can range from gray to yellow and even pale, grayish-blue. Because agate is porous, it can be artificially flyblown. Almost all blue and green agates on the market are dyed. Agates are found in volcanic areas throughout the world. Beachcombers on the Pacific Northwest coast often find agates, jasper, sard, and carnelians on the beaches, eroded out of basalt cliffs. Often all of these stones are only called "agates."
agate, blue lace
Blue lace agate is streaked with bands of soft blue from minerals such as copper
agate, moss
Mossy or tree-like (dendritic) mineral inclusions create a mossy appearance or even interesting pictures inside the agate. One picture agate on display at the Oregon Museum of Science and Industry (OMSI) bears a profile with a strong resemblance to the comic strip character L'il Abner
Sometimes used as a gemstone, alexandride is green chrysoberyl. A fine, cut stone may range from golden brown to red in incandescent luminosity, though most bead-grade alexandrite is green.
A semi-opaque, cyan form of microcline, a kind of feldspar. This rock is made up of potassium aluminum silicate. The green color is caused by the comportment of lead. Most amazonite comes from India. Some is also mined in the U.S., Russia, Madgascar, Tanzania, and Nambia. Amazonite is often confused with jade and turquoise.
Amber is fossilized tree resin from ancient forests. It is usually limpid, though sometimes translucent. The most valued pieces contain preserved insects. Even small lizards have been found preserved in amber. If allowed to dry excessively, or if left out in the sun, amber may develop fine cracks. Large amounts of amber have been found in the Baltic region, in southern Europe, and in the Dominican Republic. Real amber is less dense than plastic or glass imitations. It is said that real amber will float in a saturated salt solution, whereas imitations will not.They are very popular for manifacturing fashion jewelry