COULEE ROCK CLUB AND BLUE VEZSELYITE

 

The Coulee Rock Club, based in Wisconsin’s Driftless Area (see end paragraph), working with the Show Chair Allison and her crew, held its annual rock, mineral, fossil, and jewelry show and sale during the second weekend of June. By all accounts, the event was a resounding success, drawing an estimated attendance of ~1600—perhaps the largest turnout in recent memory. Visitors streamed through the doors from Saturday’s opening to Sunday’s close, and the vendors I spoke with seemed pleased with their sales. As rock and mineral shops continue to close across the country, shows like the Coulee event may be the best—and perhaps last—places to view genuine specimens in person and to chat with dealers and other rockhounds in an informal environment.

You just can’t beat two bucks a head complete with friendly conversation!

My “job” for the show was as a greeter and font of knowledge about all things geological, especially where to collect Lake Superior Agates: ANSWER-- examine all decorative river-derived gravel lining flower beds, sidewalks, etc. as you walk around town; 2) visit a local landscaper and obtain permission to examine their landscaping gravel; and 3) join our rock club and attend the field trips walking or canoeing the sand bars in local feeder streams. In my opinion, it is much easier to collects agates in downtown La Crosse along the Mississippi River than to scour the shorelines of Lake Superior.

Meet Mr. Castoroides, a bear-size beaver who only became extinct about 10,000 years ago.

As a greeter I was trying to attract, and visit with, the younger clientele who were tagging along with their parents or grandparents---get them interested at an early age. I was fairly successful since I brought along some of my casts of a Pleistocene Giant Beaver and a Dire Wolf along with the giant claw from the Oklahoma  Allosaur. I also had a bag filled with small “pretty rocks,” mostly shiny and siliceous, as a “give-a-way” to entice their interests. Often, youngsters know a large amount of information about fossils and they like to tell anyone within earshot. Bring ‘em on; KIDS ROCK!

Buyers were waiting when the doors opened.

I am not an avid agate collector nor a lapidary, both major hobbies of many of our club members. These interests relate to our local bedrock geology—outcrops of Cambrian sandstones and Ordovician carbonates with the latter often containing siliceous vugs or nodules and at times calcite crystals, and the gravels and cobbles containing agates along the River. However, the club also sponsors exciting collecting trips to the Black Hills and adjacent outcrops, Moose Lake, MN agates, Wisconsin moonstone, agate rivers of Montana, Keokuk concretion rocks of Missouri and Iowa, amethyst quarries near Thunder Bay, Ontario, famous Native American quartzite quarries, and fluorite localities in Illinois and Kentucky. See Couleerockclub.org for information.

I prefer to visit dealers with a selection of interesting and non-common minerals—no pyrite, calcite nor quartz! And sometimes these dealers are tough to find her in the Midwest, unlike shows in my previous abode in Colorado.  Therefore, I was pleasantly surprised to Find SS Rocks from up the road in Oshkosh, WI. SS Rocks hits many of the rock and mineral shows in this part off the Midwest but also has a large EBAY presence with auctions and a store (ssrocks2015). They simply have a large collection of minerals from many parts of the world and quite reasonable prices.

Several local members of the Coulee Club participated in the dealerships of the show with wares ranging from jewelry to agates to local/semi local minerals. I was most interested in a large hunk of amethyst-bearing rock collected from the quarries near Thunder Bay, Ontario, hauled back by Apryl.  It certainly is more exciting than Cambrian sandstone road cuts! Jay and Jana, agate slicer and ring maker extraordinaire, worked tirelessly to clear away hundreds of  specimens via the club silent auction.

A regular dealer at the Coulee Show is “Mr. Wisconsin Agate” Doug Moore from up the road in Stevens Points. Doug is a masterful agate collector and agate photographer and is known worldwide for his spectacular prints and posters, especially of those collected from Germany (over 30 trips since 2002), the Lake Superior region of the Midwest, Oregon thundereggs (a book in is the works), and Fairburn types from the Black Hills region. Check out this QR code for some of Doug’s photos.

 

So, one of my purchases this year from SSRocks was a nice blue mineral (I seem stuck on blue minerals), veszelyite, a hydrated copper zinc phosphate, [(Cu,Zn)₂Zn(PO₄)(OH)₃ · 2H₂O]. As a rare secondary mineral found in the oxidized zone of some polymetallic mines rich in copper and zinc. The “blue” color, often quite vivid, comes in a variety of shades from the well-known electric blue, to royal blue and cobalt blue, to turquoise blue-green, to mostly green to light blue. The crystals are vitreous to subvitreous, and rather soft (~4.5 Mohs).  Larger crystals are identified as Monoclinic and flattened or elongated Prismatic. However, many specimens contain quite tiny, bladed crystals or granular aggregates and are difficult for me to locate well-formed crystals.

The matrix of the specimen consists of tiny botryoids of hemimorphite [Zn₄Si₂O₇(OH)₂ · H₂O]. Note some blue veszelyite showing through. Width FOV ~ 6 mm.

Veinlet of intense blue veszelyite in a mixture of matrix hemimorphite and lighter blue veszelyite. Width FOV ~6 mm. The green botryoids are hemimorphite or perhaps cuprodongchuanite, a lead zinc copper phosphate.  Width FOV ~6 mm.   

A vug (~2 mm) in the matrix containing microscopic crystals of veszelyite with a partial covering of two shades of green botryoids.

Submillimeter aggregates (darkest intense blue) of flattened plates of veszelyite crystals. Best crystals I could locate and get a photo.

Veszelyite is a rare mineral and for decades most specimens, never common, came from Africa and Europe (Type Locality in Romania, 1874) although the Black Pine Mine in Montana produced what was/are the finest crystals. Then recently, in the last decade, magnificent and numerous specimens hit the market from the Dongchuan Copper District, Kunming, Yunnan, Peoples Republic of China. The Dongchuan Mine in the District is the source of my specimen.

The District is a major producer (third largest) of copper utilized by the industrial giants of China. The copper ore is found in sedimentary rock-hosted, strata-bound deposits and has been mined for centuries. One early use of the copper was to mint bronze coins (an alloy of copper and tin) during the Quig Dynasty, the last imperial dynasty of China (1644-1912). MinDat noted the District has produced 84 valid minerals including 7 types (mostly colorful tiny phosphates). It is well known as a collector’s paradise.

FYI: The Driftless Area is a topographic and cultural region that comprises southwestern Wisconsin, southeastern Minnesota, northeastern Iowa, and the extreme northwestern corner of Illinois. It was never covered by ice during the last glacial period, so the area lacks the characteristic glacial deposits known as drift. Its landscape is characterized by steep hills, forested ridges, deeply carved river valleys, and karst geology with spring-fed waterfalls and cold-water trout streams. Ecologically, the Driftless Area's flora and fauna are more closely related to those of the Great Lakes region and New England than those of the broader Midwest and central Plains regions. The rugged area near La Crosse (my home) is known as the Coulee Region due to the steep and deep canyons (coulees) cutting through the River bluffs to Base Level (the Mississippi River). Many areas in the bluffs are ~ 600 feet above the River and offer amazing views (see Grandad Bluff). Mt. La Crosse Ski area near the south edge of the city has a vertical drop of 516 feet and is a major destination in the area. It just a pretty nice place to live and enjoy life.

Above paragraph extracted from Wikipedia July 2026. 

TURQUOISE: FAKES, FRAUDS AND CRYSTALS

 

Turquoise is one of those minerals recognized by “almost everyone.”  It is a hydrated copper aluminum phosphate that is most often found in  phosphorus-rich alteration zones of porphyry copper deposits that have been subjected to infusions of hydrothermal solutions. There are also minor turquoise occurrences: 1) in volcanic rocks such as Cripple Creek, Colorado where the mineral formed in cracks and faults associated with the gold-producing volcanic caldera; and 2) as nodules in phosphatic rich rocks subjected to meteoric (rainwater) water infiltration such as the Sanders Project in North Carolina.

R.J. King, in a great 2002 article in Geology Today, explained, in a very understanding manner, the complex formation of the porphyry copper model: as a supergene mineral turquoise forms when meteoric water percolates down through the copper porphyry minerals and rocks. Dissolved oxygen in the water oxidizes the copper sulfides to soluble sulfates, and the acidic copper-laden solution then reacts with aluminum and potassium minerals in the host rocks and turquoise is precipitated at a relatively low temperature (~200-400 F).

I rarely collect or purchase turquoise since :1) the “good stuff” from reputable dealers seems quite expensive; 2) I have not taken the time to examine closely the material from different localities; 3) the market is full of: A} dyed minerals forming imitations of turquoise; B} various synthetics (plastic) produced to closely resemble gem quality material: and C} who knows how the gems have been treated, hardened, or stabilized with polymers or resins. The latter is a legitimate process since it hardens a soft and often porous stone producing a more durable gem and often enhances the color. Reputable dealers will inform buyers about any stone treatments. What is often untold to buyers examining less expensive jewelry is that the tiny pieces or chalky turquoise (unsaleable as is) is first ground to a power and then mixed with resins and usually a color enhancer and poured into block molds. Craftsmen then cut the block in smaller pieces, form a shape, polish, and stick the creation into a ring or pendant. Perfectly legit I guess but dealers just need to inform buyers. I have purchased pendants for youngsters cut from a block, attached to backing, polished and set---and they were beautiful.

Two minerals that are quite involved in the fake turquoise market are howlite and magnesite. The former is a hydrated calcium borosilicate that is porous and veined with impurities. The subvitreous luster and the texture of the mineral allows for easy dying with various shades of blue materials, that along with the veining, certainly “resembles” turquoise. However, diluted hydrochloric acid will turn howlite a green color.

At most rock and mineral shows several jewelry vendors will display rings and pendants with stones labeled White Buffalo Turquoise, generally white in color (to honor the sacred white buffalo animal; marketing at its best). That name is a real misnomer since the stone is composed of calcite, dolomite and dark iron oxide---no copper, aluminum or phosphate, but depending on your source perhaps quartz, zeolites or magnesite. Sellers go to great length to disguise this fact but pressed will say it is “not actually turquoise but of the same family or is found with turquoise or is the favored stone of Native Americans.

White buffalo turquoise is a trade name and officially “true” white buffalo comes only from a single mine near Tonopah, Nevada. However, the majority of white buffalo being marketed is actually howlite, and has been described by some dealers as rare, even rarest of its kind, limited in extremely quantity (so buy right away), unique, avoid moisture, sunlight, heat or humidity (but scientific properties make it resistant to damage),  popular as Native Americans use it to honor their heritage, a powerful healing stone, brings clarity to decision making, one of the oldest known gemstones in North America and you name it etc. There is a long history associated with the marketing of white buffalo, and this information, although interesting, is far beyond the scope of this small article. 

So, then there is “magnesite turquoise” often marketed as turquoise (dishonest) or magnesite turquoise (at least partially honest).  The mineral magnesite is a soft, white or pastel magnesium carbonate that like howlite may be dyed and passed off as turquoise. Unlike howlite-type turquoise, turquoise magnesite, as a carbonate, will effervesce in dilute hydrochloric acid. Karl Sawyer in 2026 Lil Gem noted: “magnesite turquoise is a captivating gemstone that has intrigued jewelry enthusiasts and collectors alike with its striking appearance and unique origins. Often admired for its vibrant blue-green hues and intricate veining, this stone offers a beautiful alternative to natural turquoise, blending aesthetic appeal with fascinating geological characteristics.” On the other hand, Crystal Alamac dot com stated:  turquoise is the most-faked gemstone in the world. An estimated 90% of ‘turquoise’  sold cheaply is actually dyed howlite, dyed magnesite, reconstituted turquoise dust, or plastic. Buyers beware; “you get what you pay for,” and trust your reputable dealer.

Everything about the physical properties of turquoise seem variable. The hardness (Mohs) is usually listed as 5.0-6.0 although the material at Cripple Creek, Colorado, has a hardness of 7.0 (Mohs). The color is listed by MinDat as bright blue, sky-blue, pale green, blue-green, turquoise-blue, apple-green, green-gray. The luster can range from quite “shiny” subvitreous to earthy and dull. It occurs as veinlets or nodules or crusts or massive or cement filling in breccia.

Turquoise is CuAl₆(PO₄)₄(OH)₈ · 4H₂O and forms a solid solution with chalcosiderite where the aluminum is replaced by ferric iron (Fe³⁺). There is also a solid solution series between planerite where the CuAl₆ in turquoise is replaced by aluminum phosphate Al₆(PO₄)_2. Turquoise is much more than a pretty blue mineral—it is variable and complex.

Polished turquoise on backing labeled Courtland, AZ. Specimen 4.5 cm X 4.5 cm.

Turquoise nugget, with matrix, labeled Bisbee. Width FOV ~3.7 cm.

Specimens of turquoise purchased at a rock show 30 years ago. Both ID and locality could be suspect!   

As stated, I rarely hunt for, or collect, turquoise although I have a few specimens. However, at the 2026 Tucson Show a turquoise specimen from Shannons Family Minerals really caught my eye. Something my limited knowledge of minerals had not realized existed---turquoise crystals. Not the nodules or soft crusty material but honest turquoise crystals. Wow, always nice to get a pleasant surprise to increase your knowledge base. 

  

 

 

 

 Specimen of matrix plus blue to blue green to pale blue band of turquoise crystals. Width of top, reverse, and lower, obverse views  ~1.4 cm. 

The best recognizable turquoise crystals, at least in the U.S, are from the Bishop Copper Prospect near Lynch Station, Campbell County, Virginia. The Copper Prospect is in the old iron (late 1700s – 1880s) and manganese (~1868 – 1945) belt in the James River- Roanoke River Mining District. Crystalized turquoise evidently was reported from the area in 1910 in a Bureau of Mines publication (Sterrett). W.T. Schaller of the USGS acquired a specimen (from J.H. Watkins) of the turquoise and reported on its physical, chemical and optical properties (1912); however, the rareness and lack of outcrops evidently scared most prospectors away from the area and it was not until the early 1940s that local collectors sort of rediscovered the source of the turquoise. In the 1960s local collectors started working the old mine dumps rather than attempting to locate specimens in the deserted manganese mines and were somewhat successful. Bland (1963) wrote, “in order to obtain good material, one must did through a mixture of dirt, roots and logs… and at the three-foot lever, one runs into a layer of brown to black mica [and below this] a layer of schist and quartz fragment [and it becomes necessary to wash every piece to locate turquoise crystals].” For years the Bishop Copper Prospect seemed the only locality of crystalized turquoise. However, by Barwood’s 2003 publication 26 other localities were recognized. Unfortunately, I have been unable to locate a seminal paper with all localities listed and the number of localities may now exceed 27. I suppose one could sort through all MinDat turquoise localities and try to locate crystalized specimens. For example, I found the Bachman Mine in Pennsylvania listed turquoise as present and David Fryauff has posted a photograph of the crystals. For me, another project for another day. This information about the Bishop Copper Prospect was retrieved from a Mineralogical Record article by Henry Barwood (2003).

Extreme closeup photomicrographs of turquoise crystals. The limit of my digital camera. The FOV for each is ~1 mm or less.

Hundreds, probably thousands, of articles and a large number of books describing turquoise have been penned by a variety of worldwide authors, including the description of King Tyre in the Christian Bible: "You were in Eden, the garden of God; Every precious stone was your covering: The ruby, the topaz and the diamond; The beryl, the onyx and the jasper; The lapis lazuli, the turquoise and the emerald; And the gold (NASB version, Ezekiel 28:13). The gem has a long known history as it was mined in the Siani of Egypt since at least the First Dynasty and possibly before—at least 3000 BCE. The Chinese have mined turquoise since at least the Shang Dynasty ca. 1600–1046 BCE. In the U.S. Native Americans mined the gem in the Cerrillos Hills of New Mexico over a thousand years ago. So, readers, explore the internet and libraries and your reading about turquoise will last a lifetime.

REFERENCES CITED

Barwood, H., 2003, Famous mineral localities: The Bishop copper prospect near Lynch Station, Campbell County, Virginia: Mineralogical Record, vol. 34, no. 3.  

Bland, R. J. Jr., 1963, Operation turquoise crystals: Rocks and Minerals, vol. 38, nos.11-12, November-December).

King, R.J., 2002, Turquoise: Geology Today, vol.18, no. 3.

Schaller, W.T., 1912, Crystallized turquoise from Virginia: American Journal of Science, vol. 33.

Sterrett, D.B., 1910, Gems and precious stones: Bureau of Mines, Mineral Resources of the United States, Part II--Nonmetals.