Fuchsite

A beautiful blue area therefore needs to be understood as a material, with its own structure, rather than treated simply as color waiting to be shaped.

Fuchsite is the name commonly used for chromium-bearing muscovite, a member of the mica family.

Mica's thin sheets help explain its characteristic glints.

In a rock, many small flakes can give a surface a lively, shifting appearance as the light changes.

Ulrich identified Marguerite.

Later work recognized Fuchsite as well.

A green surround that looked like a backdrop to the main attraction was gradually becoming a subject in its own right.

There is a practical difficulty here.