The process involves many steps and careful attention to detail. An expensive special agate must be used to insure a pure color. This special agate is gray and free from any naturally occurring coloration. The blue onyx produced is as delightful as a summer sky. Brazilian Agate Brazilian agate is formed in the same manner as all agate.
Agate is a quartz mineral originally formed in the bubbles within a volcanic lava bed.
When lava is released from within the earth, it contains dissolved gases. As the confining pressure decreases, gas bubbles form in the viscous lava. The bubbles range from marble size to several feet in diameter. Sometime later, hot hydrothermal water solutions containing dissolved quartz percolate through the lava beds filling the gas bubbles with liquid. Changes in chemistry and temperatures precipitate the dissolved quartz out of the solution lining the bubble cavity with extremely fine layers of crypto-crystalline quartz.