It also forms during metamorphism in schists, quartzites and marbles. Schorl is found in all of these environments. Elbaite is restricted to complex granitic pegmatites, where it may form large gemmy crystals with gorgeous colors, often arranged in zones. Tourmaline crystals 2 to 3 cm. It forms tiny blue-green prisms associated with apatite, rutile, zircon and epidote.
Tourmaline is common in the many small complex pegmatites exposed in sec.
Dark blue to nearly black tourmaline crystals occur in individuals and sprays with separate crystals up to 12 cm. The blue tourmalines may also be zoned, with light blue cores and dark blue rims. Tourmaline occurs as a widespread accessory mineral in chloritic gneiss exposed in sec. Green acicular tourmaline crystals up to 1.2 cm. Black tourmaline is also found rarely as crystal segments up to 1 cm.