Riebeckite • Na₂(Fe²⁺₃Fe³⁺₂)(Si₈O₂₂)(OH)₂
This remarkable Riebeckite comes to you from Gold Camp Rd, near Colorado Springs, Colorado, and it's now waiting to come home with you at https://ColoRockCo.com/Shop/Riebeckit....
Riebeckite has a hardness of 5 - 5 and a specific gravity of around 3.44 and was named for Emil Riebeck, a German explorer, ethnologist, and mineralogist.
It's found in roughly a couple hundred locations worldwide on every continent, with 23 locations in Colorado, often near "alcalic granites, syenite and undersaturated rocks. Rarer in felsic volcanics and granite pegmatites; also in some schists" according to Mindat.
Riebeckite is not really of any significant source of value, as this Iron- and Sodium-bearing mineral isn't significantly useful as any kind of ore or an indication of any additional valuable minerals nearby, perhaps with the exception of Zircon and TItanite on occasion, but it's a remarkable mineral and prized by Colorado collectors all the same!
If you just so happen to be out on a hike and see a mineral like this, now you may be able to recognize Riebeckite for yourself!