Colorado Collecting Trip

The July '98 issue of Rocks and Minerals magazine featured an article about Colorado barite that galvanized my obsession for collecting this fascinating mineral. Barite is rare in these parts (Massachusetts), so when an opportunity arose last September to attend a medical educational conference in my profession at the Keystone Resort, southwest of Denver, I suddenly developed a vital need to learn about “Advanced Esophageal Motility and pH Monitoring”. I contacted the author of the R&M article who offered me some locality suggestions, and off I went in search of barite. A twist of fate (and lapse of attention) turned this into one of my best field trips.

At the close of my two day conference (yawn) I headed south from Keystone, a ski town at about 9,000 feet elevation, towards Hartsel, a locality known for blue to grey-yellow barite, said to be open for collecting. My route took me over the Hoosier Pass, elevation 11,000+ feet, where my visual fields began to dim, and it got a little harder to think straight due to an altitude effect on my flatlander circulatory system. I remember wondering why all the other drivers were sheepishly observing the impossibly low speed limits. In my rush to get down to a richer atmosphere, I encountered the sole police officer in the town of Alma, “The Highest Incorporated Town in America”, it said on my speeding ticket.

As I tried (unsuccessfully) to wriggle out of this citation, I complimented Alma’s finest (and only) on his mineralogically famous town, being the location of the Sweet Home Mine, and its world class rhodochrosite. To my delight, the officer pointed out that the Sweet Home was having an open house that same day. I had heard on the Internet that Bryan Lees’ crew sporadically admitted people for tours of this - locality. I had previously dismissed my chances for a tour as nil, so I never considered looking into it. But this was my lucky day, and the policeman led me to the well-maintained access road. A few minutes later I stood before the mine portal and equipment shed, talking with a miner, ogling a large matrix specimen of rhodochrosite on a bed of quartz needles.

Soon, Dean, the mine geologist appeared and began the tour with a description of the mine’s history (originally a mediocre silver mine where rhodochrosite was discarded), followed by a talk on the local geology. We donned hard hats with miner’s lamps, rubber boots, provided by the crew, and were led into the adit itself. Along the way, we were informed that Bryan Lees was a fine mine operator and employer, as Dean pointed out the infrastructure features, such as the ventilation, power, and water supply lines, and the safe haven room, in the event of a cave-in. We passed 70-year old graffiti, and finally a storage area laden with recently found matrix specimens of rhodochrosite, hubnerite and fluorite. We were led past the locations of famous pockets, which have produced the best rhodochrosites ever found. Shards of red were scattered here and there on the floor of the adit. (Yes, some of them found their way home with me.)

Outside, I collected on the fresh dumps for several hours, finding a few quartz vein specimens of rhodochrosite rhombs to ¼”, sprinkled with fluorite and hubnerite, as well as numerous loose cleavages of rhodochrosite to 3/8”. While I was there, a group of schoolteachers were chatting as they casually looked through the dirt, and one found a deep red 1” rhomb that still takes my breath away. Whatever high altitude effect I experienced just didn’t seem to matter anymore as I scrambled around the dumps on that bright cool afternoon.

With only a few hours of daylight left, I decided to head for Hartsel, some 30 miles south, a distance that I covered at a crawl. The unspeakable beauty of the broad empty valleys between bold mountains in the late afternoon light almost made up for the fact that the Hartsel locality was closed, locked up tight behind high fences. My speeding ticket saved this collecting day.

I stayed that night with friends in Fort Collins, and set out the next day to the Stoneham blue barite site in northeastern Colorado. This locality is well known for the gemmy blue-grey barite prisms with beveled or flat terminations, founds in seams in clay matrix. A large matrix specimen resides in the hallway display case outside our BMC lecture hall at the Harvard Peabody Museum in Cambridge. The Stoneham site is also known for its accessibility, which I confirmed by asking permission from the landowners on this vast nearly empty plain. The owner simply wanted to confirm that I was hunting for barite (and, I guess, not for arrowheads). The escarpment in which the barite is found is surprisingly well hidden in this otherwise featureless terrain.

No hints of the barite seams were apparent to me, however. Collecting began with spotting glistening needle or lath-like crystals laying on the surface of the eroding slopes. Soon, it was apparent that they were concentrated in runoff gullies that veined the slope. Eventually I found a conical mound over which hundreds of small crystals had eroded out. A few clusters of crystals weakly cemented together were also found here. Attempts to dig and screen these areas were frustrated by the chocolate bar-like consistency of the moist clay immediately below the surface. By the end of the day my largest individual crystals were 11/2” long by ¼” wide. Most of the larger specimens are marred by contact points from their original cluster-mates. Most however are water-clear and well formed, pseuodo-hexagonal prisms. This site is probably best visited in the spring to take advantage of erosive forces on this stubborn clay medium.


A week later, the fifty pounds of Alma specimens that I had shipped arrived at my house in Massachusetts to be trimmed and cleaned, allowing me to relive the trip.

Addendum 9/02: The Stoneham barite locality may now be closed.

Paul Gilmore

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