HaŁyne tephrite ( Auvergne) thin section.

 

Sample taken from the "Banne d'ordanche, Monts Dore, France". Big crystal of ampphibole (green in plane polarized section). At the top left, feldspathoid crystals isotropic in LPA (dark) can be seen, better viewed in LPNA. Plagioclase matrix.

A few olivine crystals are also present in the rock..

 

 

     Plane polarized view