�y��vlog

The stone has the scientific name of “blue zoisite”, but it was given the name “Tanzanite” to help it sell better.

Zoisite, zoi′sīt, n. a mineral closely allied to epidote.

When this substance can be resolved by the microscope it proves to consist usually of zoisite or epidote, with garnet and albite, but mixed with it are also chlorite, amphibole, serpentine, prehnite, sericite and other minerals.

Their hornblende in microscopic section is usually dark green, rarely brownish; their felspar may be clear and recrystallized, but more frequently is converted into a turbid aggregate of epidote, zoisite, quartz, sericite and albite.

They are principally finely divided quartz, epidote, zoisite, rutile, limonite, calcite, pyrites, and very small particles of these are rarely absent from natural clays.