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. 

 

 

CARBONATECYANOTRICHITE: BLUE AND PRETTY

 

During my 2026 ramblings in Tucson looking for small goodies, especially those blue in color and stuck in Perky Boxes, I stumbled across a specimen of carbonatecyanotrichite. I took a quick peek with my hand lens and decided it had my name all over it. Without any other thoughts I presumed that it was cyanotrichite (Cu₄Al₂(SO₄)(OH)₁₂ · 2H₂O), a secondary copper mineral from the oxidized zone, with some carbonate thrown into the mix. In fact, when the mineral was first described (Ankinovich and others,1963), the authors noted it was a variety of cyanotrichite. In returning home and looking at the specimen of “cyanotrichite”, I decided that it: is a gorgeous mineral; the chemistry is complex; and my guesses are usually “wrong”. This entire, confusing situation reminded me of the great poet Robert Frost—I’m not confused. I’m just well mixed.

So, every curious rockhound then descends in a deep dive into the literature “trying to find answers to life’s persistent questions” (Guy Noir, Private Eye). However, PE Noir and I failed to locate many answers to anything and agreed with Hager and others (2009): “final resolution of the nature of individual members of the [Cyanotrichite] Group awaits single-crystal studies when suitable crystals become available… “ Those Group members (closely related, monoclinic Cu-Al-sulfates) include: cyanotrichite, carbonatecyanotrichite (usually with carbonate), camerolaite (antimony rich) and khaidarkanite (fluorite rich), a Co-rich member of the group from the Grandview mine, Arizona, and a cyanotrichite-like phase from the Clara mine, Germany.  Mills and others (2014) solved the crystal structure of camerolaite and suggested a structure for cyanotrichite. What Private Eye Noir and I learned from this deep dive is that although cyanotrichite and carbonatecyanotrichite were once thought to be closely related or even varieties, Hager (2009) pointed out that there is no evidence that a solid solution series exists between the two minerals. What we have is four, or more, similar minerals that are impossible to distinguish without the use of electronic gizmos such as a single crystal x-ray diffraction unit.  

So, since my single crystal XRD is on the blink, how do I know that specimen presented here, and collected from the Qinglong Mine, Qianxinan, Guizhou, China, is carbonatecyanotrichite? I am taking the word of my dealer, and from Robert Lavinsky who noted in MinDat that “the Qinglong Mine in Guizhou, China is the only confirmed source for the species in the entire country. Specimens started trickling out in the mid-2000s (originally labeled as cyanotrichite - but it should be noted that many of the world occurrences for "cyanotrichite" are turning out to be carbonatecyanotrichite upon analysis), and are very few and far between these days on the market.” Now I really appreciate the words of the non-geologist Winona Ryder: when you finally accept that it's OK not to have answers and it's OK not to be perfect, you realize that feeling confused is a normal part of what it is to be a human being.

As I noted above carbonatecyanotrichite is a stunning mineral with a sky-blue, or at times an azure blue, color. It is very soft at~2.0 (Mohs) and has a silky luster. Transparent to translucent crystals are acicular or needle-like in appearance. In fact, the root word of cyanotrichite is derived from the Greek words: kyaneos = blue and triches= hair.     

Mass of hair-like crystals of carbonatecyanotrichite. Width FOV ~ 7 mm. Arrows point to unknown minerals noted below. Mineral 6 may be darkest purple fluorite or limonite.

Number 1: spherules of a very dark, ?black “nest”. My best guess limonite, Number 3: ?tan crystals without a definite shape. Both are in a vug. The matrix appears to be quartz with a few patches of fluorite.

Mineral 2: bundles of dull white prismatic crystals. My best guess is baryte. Mineral 4: white balls less than .15 mm in size. Possibly calcite.

 

Mineral 5: prismatic black crystal of perhaps stibnite. The very slender crystal seems perched on limonite and covered with such.

This specimen has been a tough one to decipher as the non-blue minerals are tiny, all a fraction of a millimeter and beyond the limits of my scope. As Daniel Boone stated,  I have never been lost, but I will admit to being confused for several weeks.

REFERENCES CITED

Ankinovich, E.A., I.I. Gekht, and R.I. Zaitseva,1963, A new variety of cyanotrichite - carbonate-cyanotrichite: Zapiski Vserossiyskogo Mineralogicheskogo Obshchestva: vol. 92.

Hager, S., L P. Leverett, and P.A. Williams, 2009, Possible structural and chemical relationships in the Cyanotrichite Group: The Canadian Mineralogist, vol. 47, no. 3.

Mills, S.J., A. G. Christy, C. Schnyder, G. Favreau, and J. R. Price, 2014, The crystal structure of camerolaite and structural variation in the cyanotrichite family of merotypes: Mineralogical Magazine, vol. 78, issue 7.