FMF - Friends of Minerals Forum, discussion and message board

[RockHunter]

I googled clinozoisite and mostly came up with chemical formula name etc... I am more interested in how was it formed?

What condition(s), what kind of environment is needed in order to develop clinozoisite?

I got the gist that clinozoisite exists in a regional/contact metamorphic with high calcium content?

[Roger Warin]

Clinozoisite.
Plagioclases alter in two ways: The alteration of acidic plagioclases is sericitization: the crystal is covered with a felting of small flakes of sericite (microcrystalline muscovite).
The altered plagioclases then take on a porcelain or slightly greenish tint.

The alteration of basic plagioclases formed at higher temperatures is more complex: it is saussuritization, obtaining a mixture of albite and epidote. In the epidote, the replacement of Fe3 + by Al3 + induces the continuous formation (solid solution) of clinozoisite while the substitution by Mn3 + gives piemontite.

The training conditions are very varied and they correspond to the metamorphism of green shales.

[RockHunter]

Thank you, Roger for your insight.