A colorful and large thumbnail of this uncommon variety of Mottramite with both Ca and Bi. This is a variety of Mottramite and not an confirmed separate specie, but was at one time. The association of Shattuckite adds a nice color contrast. This is a relatively rich specimen of a variety usually only in micromounts. The Duhamelite can be spotted by naked eye easily but is certainly best appreciated under magnification.