Dims: 2.83x2.71x1.53in (7.19x6.90x3.89cm)
Wt: 6.46oz (183g)
M T Jeannes Pit #1, San Benito County, California, USA
This is not technically joaquinite, but rather Strontiojoaquinite (Hydrated Strontium Barium Sodium Iron Titanium Silicate Oxide Hydroxide), a very close relative, also monoclinic. It is the pale brown crust exposed over much of the host rock, and intermixed with quite a number of other minerals. There is no indication of crystal form in the dull, opaque mineral, except in a few tiny patches (mostly on the back) where a loupe reveals tiny transparent pale brown crystals.