Opals, a birthstone for October, are made of hardened silica and often contain water (up to 10% ) in submicroscopic pores, making them very soft with a hardness of only 5-6. The name opal derives from the Greek Opallos, meaning "to see a change (of color)." Opals range in color from milky white to black with flashes of yellow, orange, green, red, and blue. An opal's beauty is the product of contrast between its color play and its background. Opal is a formation of non-crystalline silica gel that seeped into crevices in the sedimentary strata. Through time and nature's heating and molding processes, the gel hardened into the form of opals. When we think of opals, we often picture bright flashes of color on a white base, but the reality is that the majority of Opals contain no flash and are opaque. The most popular versions of common opaque Opal include pink and blue Peruvian Opal, yellow Ethiopian Opal, beautiful Oregon Opal, while the most impressive specimens of flashy opal include Mexican fire opal and Australian black and boulder opal. Opals don't always occur as just mineral deposits, Opal can be found as a replacement mineral in pieces of fossilized wood, shell or bone. It is believed that different kinds of Opals assist with different kinds of problems… for example fire Opal is used to assist the wearer in overcoming shyness while white precious Opal is said to assist the wearer in becoming more loving and positive.