Opalite is a trade name for man-made opalescent glass and various opal and moonstone simulants. Other names for this glass product include argenon, sea opal, opal moonstone and other similar names. It is also used to promote impure varieties of variously colored common opal.
Natural Opalite (as opposed to the man made Opalite) shares the same basic chemical properties as Opal. It is made of tiny spheres of Silicon Dioxide which stack onto each other in a pyramid grid shape. This grid is what allows the cat’s eye effect to be displayed when the stone is cut into a high domed cabochon. Natural opalite is referred to as "common opal" to prevent confusing it with glass opalite.
When opalite glass is placed against a dark background, it appears to have a blue color. When placed against a light background, it is milky white with an orange or pink glow. Because it is glass, it may sometimes contain air bubbles, an after effect of the forming process.