There is some concern about the exact locality of this mineral (although the ID label was very specific). It is reported that FMS members in the Northern CA region bought all the Datolite the Crafty Lady rock shop had, and resold what they did not want to keep. Per one of our contriubtors: "Here is what I am guessing happened. The Crafty lady did not have a location for this material so people labeled this as “From Crafty Lady Rock shop, Hopland, Mendocino Co., California. As the specimens were sold, the location was shortened to Hopland, Mendocino Co., California. Someone wanted to get a more accurate location so they looked for a nearby Datolite location in Mindat and found the Rosenhahnite occurrence. The Datolite from the Rosenhahnite occurrence looks nothing like the Crafty Lady specimens."