History · Geology
About Labrador Coast (Tabor Island, Nain)
The Labrador coast at Tabor Island and the surrounding Nain area in Newfoundland and Labrador, Canada, is the world’s type locality for labradorite — the iridescent calcic-plagioclase feldspar variety. Discovered in 1770 by Moravian missionaries, the locality has supplied lapidary-grade labradorite for over 250 years.
Geology
The host rock is the Mesoproterozoic Nain Plutonic Suite — a vast anorthosite-mangerite-charnockite-granite (AMCG) complex with massive labradorite-rich anorthosite layers. The “labradorescence” iridescence comes from ordered exsolution lamellae within the calcic plagioclase.
Notable Minerals
Labradorite (iridescent blue-green-gold-purple play of color — world-best), feldspar (broader plagioclase varieties), olivine, augite, ilmenite, spinel, garnet. Tabor Island and Paul Island anorthosite blocks supply the gem-grade material.
Collector Notes
Labradorite cabochons and slabs from Tabor Island are the species’ lapidary standard. The “spectrolite” trade name applies to particularly intense Finnish labradorite, but the original Canadian material remains the type-quality reference.
Minerals Produced Here
- Augite (普通辉石)
- Ilmenite (钛铁矿)
- Labradorite (拉长石)
- Spinel (尖晶石)
