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Hello, Hello, Hello,

I am happy to start off our blog feature with last year's trip to the Devils Hole Quarry near Cotopaxi, Colorado. To start off our blog, here is a little bit of geological information and history of the area surrounding this area.


Colorado Highway 50 stretches though one of the most interesting and complex geological areas of the Colorado Rocky Mountains. On the western end of Hwy 50 is the town of Salida, where the famous Turret Mining District is located along with the famous Calumet Iron mine. Heading East from Salida, you will pass through massive dykes of pegmatites that often contain many different crystals including tourmaline, beryl, mica, and on occasion, rare metals and minerals.

The quarry near Texas Creek is no exception to this this area in its geological value and history. The pegmatite from this area was mined during the early 19040's and the 1950's for the valuable mineral columbite. The quarry has since been abandoned but the mineral deposits are some of the most beautiful and superb.


The main material that was mined from the area was Columbite, an important ore of the metals Niobium and Tantalum. Niobium is used as an alloy for gas pipelines and as a steel hardener. It also has an application for jewelry, making for a cheap hypoallergenic plating for sensitive skin. Tantalum is mostly used in capacitors that you will find in your mobile phones, video game systems, and DVD players. both metals are considered "technology-critical elements". Other minerals in the pegmatite are as follows:

Tourmaline Var. Schorl

Beryl Var. Pink to Yellow Topaz

Biotite Mica

Muscovite Mica

Almandine Garnets


On May 28th, my father and I went to the quarry for the summers first rockhunting expedition of the year. we arrived at the quarry after a very rough ride up the washed-out road to the quarry before arriving at the quarry in 85-degree heat. We parked the truck and set it up as our base of operations, making sure that the bed was easily accessible.

When rockhunting in the middle to Southern part of Colorado, especially in the mountains, you need to think safety before anything else. Bring at least 5 gallons of water, left side, and wear layers of clothes, right side, to shed when you get too warm. And make sure to wear plenty of sunscreen and a good hat.

The big box is my rockhunting kit that I will later on show what you should and should not have for rockhunting.

Above is my father, our dog Bella, yes, she is a big dog, and a view of the bottom of the quarry tailings pile.

As mentioned before, the weather was pretty warm and very sunny, with some to little cloud cover so hats and sunscreen were being applied liberally. After several hours of exploring, clearing, and deciding, we collected the stuff we wanted.

We collected many fine specimens of the Texas Creek Pegmatite, left photo, and you can see just how big some of the pegmatite is from the middle photo. The dog, right photo, was much more interested in finding a shady spot to sleep or chase a squirrel or chipmunk. The day ended with my father and I collecting nearly 400 pounds of rocks, crystals, and minerals. A great Haul to end the day and to end the first rock hunt of the year.

Thank you for reading about our trip and stay tuned to see more trips, upcoming events, tutorials, and other big events. See you next time,

Kollin Olsen, Owner and Founder of Olsen's Minerals

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