QUARTZ and MEDUSA QUARTZ
WITH INCLUSIONS OF GILALITE
Paraiba Quartz has nice blu inclusions of the rare copper mineral Gilalite
(Cu5Si6O17·7H2O). It comes in two varieties, Medusa Quartz and Paraiba
The more sough after is the so called Bolinhas (small balls) or Medusa
Quartz (Jellyfish) that shows small globular aggregates of fibrous crystals.
The name is due to the shape of the aggregates remembreing Jellyfish.
The other variety is know as Paraiba Quartz, but both can be called
with this generic name. It is composed of fibrous gilalite crystals in
thin sheets covering a phantom inside the quartz crystal. Cut stones can
be completely blue if the table is cut parallel to the quartz face or show
an interesting bicolor when the stone is cut perpendicular to the phantom
Color is usually turquoise blue, but can be water green, more often
both colors are present in the same sample. Some red spot can be due to
the rare presence of micro native copper dendrites.
The commercial name Paraiba Quartz is used for remember the Paraiba
Tourmaline. But is true that the origin of this quartz is really from the
Paraiba State. Exactely this nice quartz comes from São José
da Batalha, Salgadinho, Paraíba, Brazil.