This in all likelyhood is a portion of the type specimen. As stated on a copy of the original label, which came with the mineral, it originated from the float boulder found by Leo Rosenhahn. Rosenhahn had Dr. Pabst (of Pabstite fame) for identification and description. Please see the "prov. tab".
The Rosenhahnite is all of the creamy white mineral. This is a portion of a larger specimen, which was in the Phillips Collection.