Opal is a hydrated amorphous form of silica, its water content may range from 3 to 21% by weight, but is usually between 6 and 10%. Because of its amorphous character, it is classed as a mineraloid, unlike crystalline forms of silica, which are classed as minerals.
Peruvian opal has a random crystalline composition, which is why it lacks the fiery attributes of other opals. This gemstone is usually coloured blue to blue-green. Most jewellers describe it as the colour of the Caribbean Sea. These stones may enclose dark inclusions that look like ferns. Also the amount of this colour may vary within a single specimen.
Opal is an emotional stone and reflects the mood of the wearer. It intensifies emotions and releases inhibitions. Encourages both freedom and independence. Opal enhances cosmic consciousness and induces psychic and mystical visions.