It is made from a brown glass in which copper oxide is mixed. Upon cooling the copper oxide changes and turns into copper crystals. The resulting glass is brown with tiny sparkling crystals of copper. Goldstone is a most popular and attractive gemstone. Only jade will make a hammer blow rebound so fiercely.
Black jade is probably the toughest of all jades.
It just bounces around. Jade is an enduring gemstone. Montana Agate Montana Agate is a quartz mineral originally formed in volcanic lava beds. When lava is released from within the earth it contains dissolved gases. As the confining pressure decreases, gas bubbles form in the viscous lava.