Wyoming - The Gemstone State

Gem-quality pyrope garnet faceted from rough collected at
Butcherknife Draw near Green River, Wyoming.

Colored gemstones were almost unheard of prior to 1977 other than some fabulous cobbles and boulders of jade, some agates, petrified wood, and a couple of tiny diamonds that required a microscope to see. After I was hired as the Senior Economic Geologist at the Wyoming Geological Survey, I began first to search for diamond deposits, then gold, and along the way, I got interested in gemstones, their geological settings and necessary conditions for formation (chemistry, pressures and temperatures) (Hausel and Sutherland, 2006). It soon became clear that several variety of gemstones should be found in Wyoming but few were ever reported. 

So I went looking and was amazed at all of the gems, diamonds and gold that had been overlooked in the Cowboy State: I kid you not - some sitting right along the highway! And I can guarantee there is a lot more, but it seems like nothing is being done since I left Wyoming in 2007 even though I had found evidence for hundreds of more diamond deposits, gold deposits, a few palladium deposits, several ruby deposits, unbelievable iolite deposits (some specimens of gem iolite as large as Smart Cars), and possibilities for emeralds and other beryl deposits (aquamarine and helidor) to name a few.

Wyoming diamonds from kimberlite, State Line district.

Over the years, I mapped more than 1,000 km2 of complex Precambrian geology along with mapping younger volcanic terrains: it became clear that Wyoming should have a wide variety of gemstones - but, there were few reports of gems found in the State and little evidence that anyone had looked. After I formulated some ideas on what to look for, I soon started making discovery after discovery. Along with these discoveries, some rock hounds were also making interesting discoveries. If only I could have been allowed to continue searching, I would have made many more discoveries.

I found dozens of gemstone deposits and likely the largest colored gemstone deposit on earth. I recovered giant gemstones (one weighing >24,000 carats) and left some in the outcrop that would dwarf my Honda Fit. A few were estimated to weigh >100,000 to >1,000,000 carats and would require jackhammers, backhoes and a dump truck to get them out! Yet these and other giant gemstones remain in situ  all because of one corrupt state geologist and his governor buddy.

I also found evidence for additional ruby and sapphire deposits in the central Laramie Range, Granite Mountains, Owl Creek Mountains and southern Wind River Mountains after finding seven previously unknown ruby deposits. And I began chasing more opal deposits where ever the countryside had been blanketed by Tertiary to Recent ash falls from past eruptions from the Yellowstone caldera (I had already found one of the largest opals on earth that weighed more than 77,000 carats with larger stones left in the field and also found a large deposit of fire opal). I was searching for other gems including possibilities of emeralds in the Sierra Madre and Overthrust belt, investigating enormous amounts of sky blue kyanite, looking for more iolites, rubies, sapphires and aquamarines, and I had verified Colorado, Montana and Wyoming was underlain by a major diamond province that to this day (2022), remains only partially explored.

Gem kyanite from Laramie
Range

It was clear, due to the unusual geology of Wyoming being a craton that was underlain by (1) very old Archean rocks (rocks greater than 2.5 billion years in age) that were subjected to very high pressures and temperatures resulting in their recrystallization and (2) some younger Proterozoic (2.5 billion to 600 million years in age) schists

and granites that had a wide variety of mineralogy and chemistry that were also subjected to high pressures and temperatures, (3) younger Phanerozoic (less than 600 million years old) sedimentary rocks, (4) Tertiary and Quaternary volcanic rocks and ash falls and (5) rare kimberlites, lamproites and lamprophyres (subjected to extreme pressures), that provide favorable host rocks for a large variety of gemstones – but no one had bothered to look.

I began to search for different gemstones keeping in mind geological environments and rock chemistry. I started to make lists of what I might find and kept extensive files on various gemstones and their geological environments, worldwide. While mapping, I was also searching for gold, base metals, strategic metals, gemstones and decorative rocks. Soon I was finding many gemstones on my list. Here is the list of what I started searching for and finding in many cases:

Giant jade boulder from Jeffrey City, Wyoming.

Agate, aquamarine, almandine, andalusite, andradite, amethyst, apatite, azurite, ammolite, apache tears, amber, ametrine, barite, bloodstone, blue chalcedony, bronzite, burgundy diamond, canary diamond, carnelian, chalcopyrite, champagne diamond, cherry opal, chocolate diamond, chromian diopside, chromian enstatite, chrysoberyl, chrysocola, chrysoprase, citrine, common opal, clinozoisite, cuprite, platinum, palladium, drusy quartz, emerald, epidote, fire (mexican) opal, fluorite, fuchsite, garnet, gold, golden beryl, golden sapphire, goshenite, green aventurine, green tourmaline, heliodor, hiddenite, idocrase, iolite, jade, jade pseudomorphs, jasper, jasperoid, jasper breccia, kunzite, kyanite, labradorite, lemon serpentine, lepidolite, malachite, maxixe, black opal, moonstone, morganite, moss agate, onyx, oriental sapphire, peridot, pink diamond, pink sapphire, precious opal, prehnite, pyrite, pyrope, quartz, rock crystal, rose diamond, rose quartz, rubellite (pink tourmaline), ruby, rutilated quartz, rutile, schorl, specular hematite, scapolite, sillimanite, silver,  smoky quartz, sodalite, spessartine, sphene, sphalerite, spodumene, star sapphire, tanzanite, tourmaline, tigerseye, varisite, white sapphire, zoisite and zircon.

A 12-carat, nearly flawless, rough pink sapphire recovered from the Palmer
Canyon deposit by Vic Norris.

The more I searched, the more I found. I spent time educating (and vise versa) rock hounds, prospectors, companies, geologists and mineral collectors in Wyoming and nearby states by providing lectures, short courses and field trips on how, where and what to prospect for. I also wrote many articles and books on prospecting. Soon I was not the only person looking for gemstones. Others began searching and finding gems in the Cowboy State. Over 3 decades, I found nearly 75% of the gemstones on my list and I suspect if I would have been able to continue, I would have found many more deposits and possibly as many as 85 to 90% of the gems.

Flawless pyrope garnet I collected at Butcherknife
Draw, Wyoming and sent to Sri Lanka for faceting.

I was asked to participate in several conferences with people showing up to my lectures carrying all kinds of minerals and rocks previously unreported in Wyoming, including materials like gem-quality labradorite found by Norma Beers (RIP) in road bed material from Albany County 11 and 12 where I had recently found a breccia pipe with limestone xenoliths adjacent to a significant kimberlitic mineral indicator anomaly that we had identified prior to 1988. Others found diamonds in anthills in the Green River Basin, and a few showed up with beautiful gold nugget specimens  (one person had more than a hundred high-quality nuggets from South Pass. Others showed me ball jars full of gold nuggets and dust from the same region, along with fantastic specimens of jasper, agate, and even an emerald still in country rock.

I had found many previously unreported kimberlites and kimberlitic indicator mineral anomalies in the Iron Mountain district near Chugwater and this attracted prospectors to dig for diamonds. I visited the Great Diamond Hoax site in northwestern Colorado where I recovered diamonds, rubies, and pyrope garnets salted by scam artists in 1872. But then I was told by Dr. Tom McCandless that Diamond Peak actually had conglomerate containing gem-quality pyrope garnet and chromian diopside (both diamond indicator minerals). What was the chance of this happening? 

Diamond companies started to show up in Colorado, Montana and Wyoming. And the Kelsey Lake diamond mine opened on the border south of Laramie - but closed 6 months later due to legal problems. Other companies picked up properties in the same region and found enough diamonds for commercial production. 

But, between 2004 to 2006, the Wyoming Geological Survey was decimated by a sociopath working for a democrat governor. For ethical and health reasons, I decided to take early retirement and run US exploration for DiamonEx Ltd, an Australian Mining Company with interests in Botswana. And I had a wonderful time until the market crash of 2008, which put many mining companies out of business.

Gem kyanite cut into cabochons from Palmer Canyon, Wyoming.
There are literally hundreds of billions of carats of this gemstone
in eastern Wyoming at Palmer Canyon, Cooney Hills, Grizzly
Creek and likely in other areas of the state (Hausel, 2009). These and other
aluminum-rich minerals are often found in what geologists call metapelite
(mica-rich schists) that was subjected to moderately high pressures and
temperatures. Using this information, I found dozens of these deposits around
Wyoming. The colors and fractures in these gems actually enhance their
appearance. I am very surprised that someone has not tried to market these
as they are relatively easy to cut. They are a low value gem, but when there
are billions of carats - who cares.

While at the Wyoming Geological Survey on the University of Wyoming campus, I had received regional and national awards for communication skills including the American Association of Petroleum Geologists President's Certificate and the Wyoming Geological Association's Distinguish Service Award for my research on Wyoming's geology and for the dozens of talks I had presented at that society. I had also been twice nominated for the Dibble Mapping Award by two former directors of the Wyoming Geological Survey - Gary Glass and Dr. D.L. Blackstone, Jr. The Laramie Lyceum had presented me Distinguished Speaker of 1994 and the University of Wyoming Department of Geology & Geophysics included me as Distinguished Lecturer and these were just some of the national and international recognition I had received over the years for being a great communicator. When I was in college at the University of Utah, I had been employed as an astronomy lecturer at the Hansen Planetarium because of communication skills. But what the heck, what did all of these people know including Who's Who in America, Who's Who in Science, Who's Who in the World, 2000 Notable American Men, etc.

I was considered to be one of the few specialists in Archean gold deposits, diamond deposits, colored gemstone deposits, greenstone belts and more. I was told by the chairman of the Geology Department at UW, that it was only because of my work and research that geologists had a good grasp of the Precambrian Geology. I had been awarded and inducted into two different Halls-of-Fame (nominated for a third) for my geological research, education efforts and communication skills, something that I suspect no other geologist in Wyoming (and possibly the US) could claim.

Giant ruby found in the Granite Mountains. This was at one time the
largest ruby ever found on earth - but unfortunately, much of the ruby
(purple red) was replaced by zoisite, clinozoiste, fuchsite (green matrix).
However, it suggests that exploration of this deposit will
potentially result in discovery of some of the largest rubies on earth.

I was one of seven geologists who  had found one of the largest gold deposits in North America, found a whole new gold district, studied hydrothermal alteration characteristics associated with a large disseminated gold and copper deposit, identified more than a hundred gold anomalies, dozens of gemstone deposits, a couple of massive sulfide deposits, one of the few nickel anomalies in Wyoming. I mapped nearly every mining district in Wyoming along with the two largest kimberlite fields in the US and the largest lamproite field in North America. 

It was time to move on, so I went to work as VP of US Exploration for DiamonEx Ltd, where I found some diamond bearing kimberlites, identified several hundred possible kimberlites for the company to explore and drill.  After DiamonEx, Ltd, I worked as a consultant for other mining companies including Black Range Resources, Giant King Gold, Strathmore Resources, Wyoming Gold, Saratoga Gold and others. Personally, I love geology and I love hunting for new mineral deposits.

Transparent blue barite from Shirley Basin, Wyoming.

Cape Emerald from State Line district, Wyoming

Banded Jasper from Tin Cup district, Wyoming

1.1 carat faceted ruby from Palmer
Canyon, Wyoming

Enormous ruby faceted from rough collected in the Laramie
Range, Wyoming

Cabochon of specularite with copper from Charter Oak mine,
Wyoming

Gem labradorite from Sybille Canyon,
Wyoming.

Malachite with specular hematite from the Hartville area, Wyoming

Geology of Gemstone Deposits

Large chlorite pseudomorph after garnet found in the Sierra Madre Mountains, Wyoming. The chlorite slowly replaced the garnet and accepted the garnet's crystal form. 

Much of Wyoming is underlain by Archean cratonic basement rocks and cratonized Proterozoic rocks that provide favorable geological environments for a variety of gemstones – notably diamond, iolite, ruby, sapphire, garnet, kyanite, andalusite, sillimanite, labradorite, jewelry grade gold, platinum and palladium nuggets, emerald, aquamarine, helidor, tourmaline, spinel, clinozoisite, zoisite, apatite, jasper, specularite, etc. Thick Phanerozoic sedimentary rock successions with lesser Tertiary volcanic rock cover large portions of the basement terrain. Some of these Phanerozoic rocks provide favorable hosts for other gemstones including opal, placer diamond, placer gold, placer platinum, placer ruby, jasper, agate, emerald, varisite, etc.

Using traditional exploration and prospecting methods, dozens of gem and precious metal deposits were discovered over the past 3 decades, including major discoveries and geological and mineralogical evidence for significant undiscovered deposits. Major swarms of mantle-derived kimberlite, lamproite, and lamprophyre, many of which have proven to be diamondiferous, also host colored gemstones including pyrope garnet (Cape Ruby), spessartine garnet, almandine garnet, chromian diopside (Cape Emerald) and chromian enstatite. One lamproite also yielded peridot.

Favorable conditions for crystallization of metamorphogenic gemstones during regional amphibolite-grade metamorphism occurred during the Precambrian. In this terrain, metapelite in the central Laramie Range hosts kyanite, sillimanite and andalusite. These three minerals provide evidence of favorable pressures and temperatures needed for crystallization of aluminous gemstones including ruby, sapphire and kyanite. Cordierite (iolite) another aluminum-rich gemstone, formed during a later thermal event. This later event was responsible for deposition of world-class iolite (Water Sapphire) gemstone deposits.

While searching for gold, I came along
this giant jasper deposit.

Evidence for undiscovered gemstone deposits is predicted based on mineralogical anomalies detected during various research projects from 1977 until 2005. These include ruby, sapphire, gold and aquamarine found in stream sediment samples as well as favorable geological terrains that remain unexplored. Other anomalies include pyrope garnet (several with G10 geochemistry), picroilmenite, and some chromian diopside that provide evidence for hundreds of undiscovered diamond deposits. Elsewhere, detrital diamonds reported by various prospectors provide direct evidence for undiscovered diamond deposits. Other geological and mineralogical evidence suggest the presence of additional undiscovered opal, cordierite (iolite) and kyanite deposits. Wyoming could potentially become a major source for gemstones including diamond, gold, platinum, palladium, Cape ruby, Cape emerald, iolite and opal.

Giant chrome diopside gem in kimberlite from Colorado.

CAPE RUBIES, CAPE EMERALDS, GARNETS

Diamonds were discovered in Wyoming & Colorado in 1975 by Mac McCallum, Chuck Mabarak & the USGS. This lead to some exploration for diamonds. Associated with diamonds are a host of extremely rare mantle nodules & gemstones known as Cape Ruby (pyrope garnet), Cape Emerald (chromian diopside & enstatite) that are always overlooked by mining companies. Yet these are very attractive, value-added gemstones. With some marketing skills, could potentially capture large parts of the colored gemstone market. For example, many Cape Emeralds are much more saturated & beautiful than emerald.

These gems were found by many prospectors and geologists all over Wyoming & northern Colorado. Large areas in the Green River & Bighorn Basin contain these diamond indicator minerals, yet little exploration has ever occurred for these or their source rocks.

Photos - Diamond indicator minerals from Sloan kimberlite, Colorado, & faceted pyropes from Green River Basin, Wyoming & Kyanite Eclogite from the Aultman 2 kimberlite, Wyoming.