Half Fast Mining Co.

07/13/2026

Stop by and see our booth at the Rapid City Gem and Mineral Show next weekend Sat. July 25 through Sun. July 26 at the nerdy nuts building at the central states fairgrounds. Both days 9am-5pm. Lots of great vendors with unique rocks, fossils, and minerals from around the globe!

07/07/2026

Last YARDSALE till next year, coming up this weekend!

06/09/2026

Half Fast Mining Co. Will be there! We have a large variety of minerals from around the world, some that we mine in the USA.
Come see
FAIRBURN AGATES
AMETHYST
FLUORITE
FINE QUARTZ
CITRINE
TOURMALINE
AND MORE
Decor and collectors minerals!

Hermosa, South Dakota
This weekend Friday through Sunday

Dates have been set for this years show. Cant wait to see everyone

06/06/2026

Citrine with Goethite inclusions.
Minas Gerais, Brazil

Do you know how Citrine gets it's color?

Iron impurities from the goethite's presence in the structure disperse throughout and cause displacement in the base structure SiO2 (Quartz). When it is exposed to natural or lab induced radiation sources this affects the distorted portion of the crystal structure called a color center, color centers are regions in the lattice stimulated by specific wavelengths of light and are reflected and perceived by your eye as a yellowish/orange golden hues.

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05/21/2026

This is a locale specific Aragonite pseudomorph after Glauberite! Primarily found near Camp Verde, Arizona. Reach out for interesting specimens from the USA for affordable prices! Half Fast Mining Co.

05/21/2026

Very geometric faces on these Arizona Andradite Garnets! Collected near Rattlesnake Butte, Arizona! Not only good shape but the camouflage green looks awesome on these one of a kind specimens! Get yours today at Half Fast Mining Co. !

05/21/2026

Beautiful specimens from the Infamous Planet Mine in Arizona! These colorful specimens are pseduomorphs of Chrysocolla after Malachite crystals. Mined in Arizona! Get yours today at Half Fast Mining Co. !

05/21/2026

Get your piece of the purest Quartz on Earth today! Mined in the United States from the World Famous Ron Coleman mine! Used industrially for fiber optics, timekeeping, lenses and much much more!
Half Fast Mining Co.

03/18/2026

Update!