Search the Web with our sponsor, Overture. It is an emerald-green color. An inclusion is a particle of foreign matter contained within a mineral.
Inclusions can be solid, liquid, or gaseous.
Many inclusions decrease the value of a stone, but some, like rutile forming asterisms in star sapphires and needles in rutilated quartz and tourmalinated quartz , are prized. Indicolite is a green to blue-green variety of tourmaline. Signet rings are frequently decorated with intaglio, as are seals . An example of an investment compound is plaster of paris mixed with silica, boric acid, and graphite. Iolite is not rare and has a hardness of 7 - 7.5.