Monday, December 22, 2014


The new episodes of The Prospectors is here again for their 3rd TV season (in the USA for my international readers).  As I understand it, this program may be The Weather Channel’s highest rated program!  The “stars” of the program are all rather “local” (Colorado Springs vicinity) rockhounds and commercial collectors and the objects of their affection include goethite, fluorite, smoky quartz, amazonite feldspar, aquamarine and topaz with a few crystals of calcite, phenakite, and clear gemmy quartz thrown in.  The collecting localities are centered on:  the Precambrian Pikes Peak batholith and especially the ring dikes of the Lake George intrusion; and the Oligocene granite found in the Mt. Antero/Mt. White area of the Sawatch Range.

Although there are tens of publications describing the geology of the Precambrian rocks around Pikes Peak, a recent article by Zito and Hanson (2014) provided a great summary: “the Pikes Peak Batholith is a composite pluton with three large compositionally similar…intrusive centers [including Buffalo Park, Lost Park and Pikes Peak].  Furthermore, the Pikes Peak intrusive center, exposed in the southern Front range, is a composite intrusion composed of a series of plutons…[including the] ring dikes of the Lake George intrusion…The…anorogenic (non-orogenic or mountain building) Pikes Peak [batholith]…formed as a result of crustal extension.”  

Pikes Peak.  Public Domain photo/drawing from USGS.
The plutonic rocks of the Pikes Peak batholith were formed from a magma  enriched with fluorine and the mineral fluorite is found as an accessory mineral appearing as massive layers, or as cubes associated the with amazonite and quartz found in the miarolitic cavities of the granite.  In addition, many of the quartz crystals are etched, probably from the action of combining fluorine and water (hydrofluoric acid).  Rare Earth minerals (REE) are not uncommon in the different batholith intrusions.  However, the major minerals sought out by rockhounds are amazonite [green microcline [KAlSi3O8], smoky quartz [SiO2] and nice large, gemmy, terminated crystals of topaz [Al2(SiO4)F,OH)2].

Smoky quartz and amazonite from Teller County.  Public Domain photo from Eric Hunt.
For a great summary of mineral collecting, and some nifty photos, I suggest readers visit the website of Mr. Rockhounding the Rockies at:


Amazonite and quartz, uncleaned, from the collection of Mr. Rockhounding the Rockies (one of the premier collectors of the Pikes Peak region).

As most travelers and rockhounds realize, Pikes Peak near Colorado Springs is named for that intrepid explorer Zebulon M. Pike.  Pike and his men were sent out by President Jefferson in 1806 (Pike Expedition) to scout the headwaters of the Arkansas and Red Rivers, and perhaps to test the strength of the Spanish government who controlled Mexico and the southwestern U.S (current boundaries)! 

Zebulon M. Pike, an extraordinary American.  Public Domain photo/drawing.
Upon entering Colorado, the explorers spotted the “Rocky Mountains” from far out on the plains, probably near Las Animas and probably Pikes Peak (although it could have been the Spanish Peaks). *** See References Cited.

15th November 1806, Saturday—At two o’clock in the afternoon I thought I could distinguish a mountain to our right, which appeared like a small blue cloud; viewed with my spy glass, and was still more confirmed with my conjecture…

Pike left behind some wonderful written records of the expedition and I enjoy reading about his travels.  So, here are a few entries from his journal, in italics, with a modern explanation (plain text).

24th November1806 Monday—We marched at one o’clock with an idea of arriving at the foot of the mountain [Pikes Peak] ; but found ourselves obliged to take up lodging under a single cedar; which we found on the prairie, without water and extremely cold.

Granitic rocks of the Pikes Peak batholith.
Pike stationed most of his group near the mouth of Fountain Creek on the Arkansas River near Pueblo where they erected a small blockade.  Pike, Dr. Robinson and two enlisted men started out to climb “North Mountain” or “Grand Peak” [Pikes Peak]. 

25th November 2006 Tuesday—March early, with an expectation of ascending the mountain, but was only able to encamp at its base…[marched] 22 miles.

They were not the last hikers and visitors fooled by the distances associated with the mountains!

26th November 1806 Wednesday—Expecting to return to camp that evening, we left all our blankets and provisions, at the foot of the mountain….after marching all day, we encamped in a cave, without blankets, victuals or water.

Every year inexperienced hikers need to be rescued off the mountain.  A couple of years ago we drove a friend up the mountain for a summer view.   Just off the summit we picked up a couple of hikers along the road (against the law to hike the road) who were being pelted by a summer sleet and hail storm.  They had hiked up during the day, missed the last train down, and were wet and tried and not prepared to spend the night.

Even today, Pikes Peak can be a dangerous place to explore.

27th November 1806 Thursday—Arose hungry, dry, and extremely sore…commenced our march up the mountain and in about an hour arrived at the summit of the chain.  Here we found the snow middle deep; no sign of beast or bird inhabiting the region…The summit of the Grand peak [Pikes Peak], which was entirely bare of vegetation and covered with snow, now appeared at a distance of 15 or 16 miles from us.

Pikes and his small group decided not to ascend the Grand Peak and noted I believe no human being could have ascended to its pinical. He started back for the Arkansas River to locate the main group and by all accounts it was a cold and hungry trip. 

In 1820, Edwin James, a young botanist traveling with the Stephen Long Expedition, camped somewhere out on the plains (presumably near Colorado Springs), and along with two companions, summited “Pike’s highest peak” in two days.  In doing so, James is credited as being the first American of European descent to summit the peak.  He also named the Colorado State Flower, the Blue Columbine (Aquilegia caerulea).
For the next three weeks or so, Pike and the group wandered up the valley of the Arkansas River and reached the current site of Canon City on the 8th of December.  By the 13th they had headed north through the hills striking the South Platte River near Eleven Mile Canyon.

16th December 1806 Tuesday—marched up the river about two miles…the doctor and myself ascending high enough to enable me to lay down the course of the river into the mountains…One of our party found a large camp, which had been occupied by at least 3000 Indians, with a large cross in the middle. Quere.  Are those people Catholics? My favorite statement from his journals!

Pike and the doctor must have been impressed with the view from their high point.  On his chart he noted the divide to the north (Hoosier Pass leading from South Park to Breckinridge), the fourteeners trending south from Hoosier in the Mosquito Range (Bross, Democrat, Lincoln, Cameron and Sherman), the majestic South Park bounded on the east by the Platte River Mountains, the Puma Hills, and the Tarryall Mountains, the Collegiate Range with its numerous fourteeners to the west, and to the southwest the mighty Sawatch Range with the fourteeners seemly rising straight up out the river valley (there is an elevation change of ~7000 feet).  I certainly am impressed every time I see that view. 

18th December 1806, Thursday—marched and crossed the mountain which lay south-west of us…on entering a gap in the next mountain came past an excellent spring which formed a fine creek [Trout Creek], which we followed through narrows in the mountains for about six miles.

After leaving the Arkansas River, Pike doubled back and headed toward the “gap in the mountains” which today in known as Trout Creek Pass and holds highway US 24/285 heading to Buena Vista and then south to Salida.
18th December 1806, Thursday—The doctor and myself went on to make discoveries and in about four miles march struck (what we supposed to be Red river) which here was about 25 yards wide, ran with great rapidity and was full of rocks.

This was actually the Arkansas River that heads near Leadville to the north.  Pike was still looking for the Red River of the south or perhaps the Rio Colorado.  During the expedition Pike did not believe the Arkansas above Canon City could have cut through Royal Gorge and appear again up in South Park.  However, upon returning Pike followed the Arkansas from South Park back to the east and came upon some of his old camp sites.  He then realized that he had been following the same river and noted on his charts that the river was the Arkansas. 

21st December 1806, Sunday—The doctor and Baroney marched [down the Arkansas River toward Salida]…Myself and the two men who accompanied me (Mountjoy and Miller) ascended 12 miles and camped on the north side [between Fisher and Riverside. 

22nd December 1806 Monday—Marched up 13 miles, to a large point of the mountain from whence we had a view at least 35 miles to where the river entered the mountains.

Pike and his two companions must have made it north to the area around Twin Lakes with a view north toward Leadville and Tennessee Pass.  His campsite is near (Twin Lakes), one of my favorite camping sites in the state.  Each fall I spend several days in the vicinity leaf peeping and camping.  Pike would have also noticed to the immediate west, two of the highest mountains in Colorado—Mt. Elbert (14,433 the second highest in the lower 48) and Mt. Massive (14,421).  

Pike came north along the Arkansas River to about the mouth of Lake Creek where it meets the river (near Twin Lakes).
23rd December 1806 Tuesday—Marched early…until sometime in the night…our clothing was frozen stiff, and we ourselves were considerably benumbed.

Pike camped again near Riverside.

24th December 1806 Wednesday—About 11 o’clock met doctor Robison…The doctor and myself pursued the trace [of the rest of the party] and found them encamped on the river bottom [about 8 miles north of Salida]…we had 8 beeves (buffalo killed by the group) in our camp.  We now again found ourselves assembled together on Christmas Eve, and appeared generally to be content.

Pike and the doctor must have hiked through Brown’s Canyon on the Arkansas south of Buena Vista before they found the remainder of the party.
25th December 1806 Thursday—It being stormy weather and having meat to dry; I concluded to lie by this day.

As I read and reread his journals I keep picturing Pike and his men on Christmas day 1806, keeping warm by the fires and having plenty of meat to eat (but without salt, or any other thing whatever). But they were warm and full!  And, I also picture them looking to the west at the mighty Sawatch Range and thanking someone that these mountains need not to be crossed.

Mt. Antero (named after the Ute Chief Antero) and Mt. White (no reference in GNIS) are located in the Sawatch Range south of Buena Vista and east of Nathrop, Colorado, and provide for a stunning view from the Arkansas River Valley. The Valley is at an approximate elevation of ~7600’ while Mt. Antero reaches 14269’, a topographic relief of 6669’. The Sawatch Range is a large Laramide (refers to a crustal shortening, compressional, mountain building event in the late Cretaceous and early Tertiary) anticlinal structure that at one time included the southern part of the Mosquito Range east across the Arkansas River. During the late Tertiary, a crustal extension event (stretching) culminated in a series of block faulted mountains and basins in in Utah and Nevada (and elsewhere---the Basin and Range Physiographic Province).  The crustal extension reached as far as Colorado where the major topographic and structural feature is the Rio Grande Rift Zone—a zone of weakness that trends from near El Paso, TX to near Kremmling, Colorado. The Rio Grande River in New Mexico and Colorado, and the Upper Arkansas and Blue Rivers in Colorado all flow in grabens created in the fault system. A graben is a down-dropped valley created by parallel faults on either side of the valley. The rift system near Mt. Antero effectively split the Sawatch Anticline into two segments, the Sawatch and the Mosquito, separated by the Arkansas River. This, and later, faulting helped create the spectacular topographic relief between the river valley and the mountain—Antero, and other mountains, simply seem to rise straight up out of the valley. 

At Mt. Antero the granitic host rock for gemstones came from a magma enriched with beryllium (as opposed to fluorine at Pikes Peak).  The major gem target at this mighty mountain is a blue variety of beryl called aquamarine [Be3Al2Si6O18].  Secondary targets found as by-products include small crystals of smoky quartz, and phenakite [Be2SiO4].

The mighty Mt. Antero.

The geology of Mt. Antero/Mt. White has been described in numerous publications, the most comprehensive being Mark Jacobson’s book entitled Antero Aquamarines (1993).  In general, Mt. Antero/Mt. White is underlain by a rock unit termed the Mt. Antero Granite. McIntosh and Chapin have assigned a date of 29.6 million years to the granite, or mid-Oligocene in age. Sharp (1976) described the granite as chiefly pinkish-orange, medium grained;… youngest of the plutons (intrusive igneous rocks) in the vicinity of Mt. Antero.  Miarolitic cavities (crystal lined cavities often containing unusual minerals) are common and are often filled with…beryl (including aquamarine), phenakite, and smoky quartz. It is from these cavities or “pockets” that come the fantastic “matrix” crystals such as the aquamarine specimen Steve Brancato collected from Diane’s Pocket in 2004. The specimen, now at the Denver Museum of Nature and Science, measures an astonishing 37” x 25”.

Prospecting for aquamarine crystals on Mt. Antero.
Voynick (2002) gives a good history of the gem mining beginning with Nelson Wannamaker in 1881. Modreski and Murphy (2002) reported an 18.95 caret, faceted aquamarine and a 15.55 caret, faceted amber topaz while Voynick (2002) noted a 50-pound smoky quartz. The area also is the major U.S. producer of phenakite. Today, many of the rock and mineral shops in neighboring towns display/sell beautiful specimens of faceted aquamarines.

But back to The Prospectors.  Pike did not note amazonite nor smoky quartz near the peak now bearing his name, nor the aquamarine at Mt. Antero.  However, he and his group covered an amazing amount of uncharted territory.  Today’s gem prospectors need to thank Pike for his exploration, discoveries, charts and maps, and general “opening up” of the vast mountainous west (although most Native Americans would not view the “opening up” as a benefit to their culture and way of life).

A final note: Brigadier General Zebulon Pike lead US combat troops in the successful attack on Fort York, Ontario, Canada (now known as Toronto) in April 1813 during the War of 1812. However, he was killed by flying debris as withdrawing British troops blew up their garrison and ammunition.


Jacobson, M.I., 1993, Antero Aquamarines: Minerals from the Mount Antero-White Mountain Region, Chaffee County, Colorado: Coeur d”Alene: L.R. Ream Publishing.

McIntosh, W.C. and C.E. Chapin, 2004, Geochronology of Central Colorado Volcanic Fields: New Mexico Bureau of Mines and Mineral Resources.

Modreski, P.J. and J.A. Murphy, 2002, A Tour of Colorado Gemstone Localities:Rocks and Minerals, v. 77, no. 4.

Sharp, W.N., 1976, Geologic Map and Details of the Beryllium and Molybdenum Occurrences,Mount Antero, Chaffee County, Colorado: U.S. Geological Survey Misc. Field Studies Map MF-810.

Voynick, S.M., 2002, Colorado Rockhounding: A Guide to Minerals, Gemstones, and Fossils: Missoula: Mountain Press Publishing. 

Zito, G. and S.L. Hanson, 2014, Minerals from the Miarolitic Pegmatites in the Stove Mountain Area, Colorado Springs, Colorado: Rocks and Minerals, v. 89, no. 3.

***Pike, Z.M., 2006, The Southwestern Journals of Zebulon Pike 1806-1807, edited by S. H. Hart and A. B. Hulbert: Albuquerque: University of New Mexico Press [all quotes by Pike are from this book].