Exceptional specimen in Sahama collection of Helsinki 19 x 16 cm, year 1966 xx to 4,6 cm [see Bancroft, Peter (1973) The World's Finest Minerals and Crystals].
Quality for species:
Excellent - world class for species or very significant. (!!)
Significance:
Classic locality for this mineral (see references.)
Keretti Mine, Outokumpu, North Karelia, Finland