azurite (w. malachite)

This specimen is from a large collection of minerals purchased by Charles Palache during his 1922 visit to Tsumeb. It was later used as the frontispiece for the Palache and Lewis (1927) azurite monograph and was the first colour image to be published in American Mineralogist. Interestingly, the photo was published in mirror image, presumably an easily committed error in the days of photographic negatives.

Palache and Lewis (1927) described the specimen as "Three azurite crystals from Tsumeb, in parallel position, altering to malachite. The concentric structure of the invading malachite fibers is well shown." A little yellowish arsenate-rich matrix material adheres but this has not been analysed. Exhibit 2 shows the reverse of the specimen.

malachite