One of us, for example, observed a sarkinite crystal over 1 cm long once thought to be the more common tinzenite.
The Val Graveglia manganese mines have produced some rare and uncommon species (bementite, ganophyllite, sarkinite, sussexite, tephroite etc.) reported from just a few other famous localities, such as Langban, Sweden, and Franklin and Sterling Hill, New Jersey (Holstam and Langhof, 1999; Frondel and Baum, 1974).
Sarkinite, a rare arsenate, was originally found in Sweden at Harstigen in Pajsberg, and at langban, and at Franklin (Dunn, 1995--1996).
I'm sure that many readers of their new book will be agreeably surprised to find that not only are these minerals chemically interesting, they are often very beautiful as well: raspberry-red sarkinite
globules, deep purple allactite, bright yellow trigonite in simple triangular plates, and some of the prettiest nadorite crystals you ever saw, adamantine yellow on their black matrix.