Neil Ray Guest Article

On the Many Variations of Bisbee Turquoise and its Identification – Geochemical Indicators and Comparisons to Kingman Turquoise

Neil Ray, West Texas Analytical Laboratory, Geochemist & Mineralogist

Bisbee turquoise has always been considered an uncommon turquoise with a rich mining history; the pit was once considered a large-scale copper mine owned by the Phelps Dodge Corporation producing substantial amounts of recoverable copper.  Consequently, turquoise was deemed a waste rock, and miners were discouraged from collecting it and they were even reprimanded for doing so.  Nevertheless, miners smuggled out significant quantities in lunch boxes or amassed as much material that they could remove without repercussions.  Interesting accounts and stories by Richard Graeme, former geologist of Phelps Dodge, can be found in Turquoise in America Part II.  One such story describes a foreman wanting a massive thousand-pound boulder of turquoise and requesting a shovel operator to place it in the back of his truck, dropping it as requested in the back of the pickup from a distance which destroyed the truck.  It is assumed that only a couple of thousand pounds of Bisbee turquoise was made available to the market, when Phelps Dodge granted a permit to Bob Matthews.  However, considering the desirability of Bisbee turquoise and the accounts of smuggling of material out of the mine by foreman and supervisors it is noteworthy to mention that the actual amount of Bisbee turquoise on the market could be much higher.  Despite the projections of a higher amount of turquoise available it is still considered uncommon and unfortunately misrepresented or confused with turquoise from other mine localities, such as the Mineral Park area of Kingman.  A considerable amount of turquoise was removed as over burden and placed in numerous mine dumps, which were once made available to the public for collecting until liability became a great concern.  Bisbee turquoise is often stereotyped with a consensus that if the material is not bright blue against a chocolate-colored matrix then it is not Bisbee turquoise.  Though it is true that bright blue chocolate matrix turquoise is easily distinguishable from other mines, not all Bisbee turquoise has this noted appearance.  The aim of this article is to examine some of the other variations of Bisbee turquoise and provide a geochemical and mineralogical examination of the Bisbee varieties and some unusual materials from the mine and how it varies chemically when compared to Kingman turquoise.

Specimens of several Bisbee varieties are analyzed by X-ray fluorescence, and the mineralogy is computed with P3M software.  Mineralogy is calculated using formula stoichiometry based on pressure/temperature, a calculation that is analogous to the CIPW norm of igneous rocks.   P3M was developed over the course of ten years of research in hydrothermal mineralogy with the addition of identifying turquoise origin from an initial pilot study provided with the help of Mike Ryan of Turquoise in America.  For those looking for an in depth read of the process, the methodology and results are available in pdf format from turquoiseinamerica.com.  We can begin our assessment of Bisbee turquoise with material that most people think of when they think Bisbee.  The specimens below are representative of the typical appearance of Bisbee turquoise with the classic chocolate matrix contrasted against the shades of bright blue that Bisbee is known for.  The specimen on the far right represents high-mid grade darker blue turquoise and the other two represent mid-grade mine run material. 

Typical chocolate matrix Bisbee turquoise, from left to right, specimens #1-#3; mid-grade (left and center) and high grade (right).

Bisbee turquoise can take on some other well-known characterized appearances such as Smoky Bisbee, which has a unique wispy pattern offset by a gray matrix.  Smoky Bisbee is one of the most sought-after varieties of Bisbee for its unique appearance.  Perhaps, the least known and difficult to discern turquoise is material that can have little or no matrix, with somewhat of an appearance that resembles Sleeping Beauty or even reminiscent of a paler version of some Nevada turquoise.  Often this variety gets overlooked as authentic Bisbee, especially in unlabeled older collections or accumulations of miscellaneous unsorted turquoise.  Finally, the most desirable is the rare spiderweb, with webbing that rivals that of some of the finest Candelaria.  Spiderweb turquoise is notably rare and specimens from Bisbee represent a small fraction of the total material that was mined.  The most exceptional are specimens, which show a deep saturated blue offset by a rich red matrix.  Spiderweb Bisbee can be difficult to discern from other well-known mines and can be easily mistaken for high grade Number 8.  Perhaps, the most unusual looking Bisbee turquoise is that with a hematite matrix that can easily be mistaken for Kingman Turquoise Mountain, particularly if the turquoise is greenish blue in color from allocation of iron.  Market naming for this material is sometimes referred to as “speckled Bisbee”, though the origin of this term is not known.  It can only be visually distinguished from Kingman by identification of the conglomerate host rock or by chemical analysis.      

Additional appearances of Bisbee turquoise, from left to right specimens #4-#6; high grade Smoky Bisbee (left), high medium grade minor matrix (middle), and very high grade spiderweb matrix (right).

Unusual Bisbee with hematite matrix, from left to right specimens #7-#8, right is end face of specimen #8 showing quartz clasts of the Glance conglomerate

A lot of material comes from collectors who obtained permission to collect from the dumps.  Though some higher-grade material is known from the mine dumps, a considerable amount of turquoise recovered from the dumps is often low grade with only small amounts of turquoise in a quartz dominated matrix.  The turquoise is often more bluish green in coloration with small discerning amounts of turquoise to be considered a suitable grade for jewelry.  Nevertheless, it is worth mentioning as to address all the possible varieties of Bisbee and to showcase the attributes of the host rock, the Glance Conglomerate.  Other notable mentions of Bisbee include the lesser-known green colored turquoise and turquoise found as veins in Quartz.  True green Bisbee turquoise is rare, representing a small fraction of the total turquoise that was mined.  The specimen below (middle) is an example of mid-grade green Bisbee, dominated by host rock matrix.  This specimen shows desirable polychrome coloration of green to greenish blue turquoise, despite being lower grade.  Another mention is turquoise found as vein material in quartz, which produces unique cabochons and jewelry pieces.  Turquoise veins in quartz are somewhat uncommon and often overlooked as natural Bisbee, because of the unique look and visual appearance of the material. 

Other notable varieties of Bisbee, from left to right, specimens #9-#11.  Low to mid-grade turquoise from Mine Dump #10 (left), mid-grade green Bisbee in host rock (middle), and medium high-grade turquoise in quartz vein (right)

                  This article thus far has outlined several varieties of Bisbee turquoise, and it has only just scratched the surface of the many varieties and appearances that Bisbee turquoise can have.  This article wouldn’t be complete without discussing the types of treatments and enhancements to Bisbee turquoise.  A considerable amount of rough collected by Bob Matthews was treated with a water-based hardener, such as sodium silicate or a non-toxic methacrylate ester-based resin.  Moreover, some material was conventionally stabilized with a diglycidyl ether epoxy resin.  It is noted that only rarely material is found stabilized with the Zachery treatment, but such turquoise shows the best quality for as close to natural look as possible.

Treated Bisbee turquoise, from left to right, specimens #12-#14.  Water based hardener (left), epoxy stabilized (middle), Zachery treated (right).

                  Considering the many varieties and appearances of Bisbee turquoise, visual identification can be difficult, unless it has the classic bright blue chocolate matrix look.  Fortunately, there are some geochemical indicators that distinguish Bisbee from other well-known mines such as Kingman.  Bisbee turquoise typically has low concentrations of molybdenum and zinc, coupled with higher silicon from a quartz dominated matrix.  Higher concentrations of molybdenum can be found in the conglomerate host rock, but not within an analysis of the turquoise itself.  The low concentrations of molybdenum, typically less than 10 ppm, help distinguish Bisbee from Kingman, which can contain well over 100 ppm molybdenum.  Unfortunately, although Bisbee turquoise has a low molybdenum content, not all Kingman contains higher concentrations of molybdenum for a clear delineation.  Some Kingman turquoise can have low concentrations of molybdenum; thus, other geochemical signatures are needed for identification.   Like Molybdenum, Bisbee turquoise typically contains low concentrations of zinc, which is often less than 1000 ppm.  Kingman can also have low concentrations of zinc, but low zinc in Kingman turquoise will often be offset by higher concentrations of sulfur.  Bisbee also has much lower concentrations of arsenic than Kingman turquoise, less than 50 ppm in Bisbee, where it is often greater than 100 ppm in Kingman.  A further distinction from Kingman turquoise can be made using the ratio of copper to iron versus the ratio of arsenic and lead as a function of available sulfur.  Most of the Bisbee specimens plot below zero and show depletion in lead and arsenic, whereas Kingman specimens show positive values indicating enrichment of sulfide forming metals.  The exceptions are specimens #4, #7, and #10, however specimens #7and #10 contain higher amounts of iron, skewing sulfide enrichment and specimen #4 is nearly pure copper end member turquoise with minimal iron substitution.  As such, either iron enrichment or depletion can display positive deviation of sulfide forming elements. 

Wt. %	#1	#2	#3	#4	#5	#7	#6	#8
SiO2	50.3873	17.7819	18.3056	3.3757	0.6500	8.0568	4.8555	84.5261
Al2O3	18.2314	38.8570	40.1995	49.2841	38.7061	37.5977	29.6605	5.0638
MgO	1.0225	1.8862	1.5621	1.7819	2.0129	2.0514	1.6895	0.8410
CaO	0.2847	3.6135	0.6070	0.3578	0.1901	0.1173	0.1757	0.0837
K2O	0.4417	0.7777	0.1791	0.2374	0.0158	0.0850	0.2962	0.0288
Na2O	1.8470	0.8480	0.1206	0.1170	0.7287	0.6516	0.3235	1.0902
P2O5	16.0791	25.7582	29.7604	33.6193	31.9420	26.9016	26.2421	1.5948
TiO2	0.0330	0.0972	0.0122	0.0221	0.0250	0.2265	0.0177	0.1184
MnO	0.0125	0.0265	0.0285	0.0105	0.0087	0.0124	0.0085	0.0102
FeO	0.8067	3.3005	0.0597	0.1017	0.5645	0.0100	0.4492	1.2226
Fe2O3	0.6880	0.0303	0.3660	1.1156	6.4123	9.2007	4.2996	1.6631
S	0.2336	0.5111	0.1938	0.1514	0.1672	1.7773	0.1400	0.3017
Cl	0.0028	0.0035	0.0030	0.0030	0.0034	0.0523	0.0034	0.0685
ppm wt.
Sr	914	4687	605	458	66	68	52	56
Ba	914	2096	876	1796	1851	269	1436	230
Rb	14	32	10	7	2	2	11	2
Zr	6	45	6	5	3	3	3	3
Mo	3	4	4	4	5	5	4	1603
V	26	58	62	34	78	96	54	17
Ni	22	29	28	30	43	45	39	31
Cu	32269	41554	62835	77593	76127	66791	68464	2043
Zn	519	455	805	891	392	436	281	100
Cr	14	17	73	92	44	88	50	11
Pb	45	70	84	6	126	25	485	5
As	5	9	13	5	23	81	42	18
W	369	87	347	207	72	68	71	47
Sb	24	23	19	10	17	19	17	14
Sn	20	22	16	16	19	22	20	26
Ag	14	21	20	10	9	13	14	10
Bi	5	9	7	6	7	17	9	4
Co	40	76	27	35	220	280	107	49
Nb	2	3	3	3	3	33	3	14
U	9	17	27	13	14	7	7	4
Th	2	4	3	3	3	11	4	3
Se	3	4	4	4	320	279	273	3
Li	4	0	0	0	0	0	0	0

Wt. %	#9	#10	#11	#12	#13	#14
SiO2	46.0238	3.7704	43.0249	13.9697	27.1866	1.8958
Al2O3	25.6396	28.8069	12.0624	31.4687	14.9597	42.8161
MgO	1.5879	2.2370	1.0014	1.8471	1.0799	2.3225
CaO	0.2163	0.0902	0.4823	0.3498	0.4516	0.1403
K2O	3.0407	0.2206	0.1206	0.3281	0.4085	4.1745
Na2O	0.3344	0.2587	4.4012	0.2571	0.3163	0.8183
P2O5	7.0707	23.4695	13.2132	20.0471	14.9173	34.1074
TiO2	0.3401	0.0197	0.0109	0.0799	0.0217	0.0151
MnO	0.1230	0.0086	0.0087	0.0586	0.0170	0.0238
FeO	7.7944	1.1238	1.2897	1.6619	0.1568	3.0844
Fe2O3	0.0578	11.7092	1.3626	11.2008	0.6964	1.1043
S	0.0730	2.1700	0.1671	0.2337	0.0881	0.1698
Cl	0.0034	0.0064	0.0028	0.0032	0.0030	0.0036
ppm wt.
Sr	28	234	155	26	519	405
Ba	1484	354	419	2370	1225	1762
Rb	119	3	2	7	3	17
Zr	201	5	3	20	5	5
Mo	4	6	3	6	3	4
V	66	101	25	84	23	37
Ni	25	45	18	58	23	31
Cu	23391	63959	13752	58990	36751	63741
Zn	589	318	105	968	236	334
Cr	126	156	14	151	32	111
Pb	86	25	131	178	60	87
As	9	573	28	26	5	15
W	108	71	153	84	100	89
Sb	24	17	36	18	58	23
Sn	15	23	22	18	49	28
Ag	20	13	18	9	22	27
Bi	21	6	5	10	5	8
Co	94	244	32	261	25	88
Nb	15	3	2	39	2	3
U	12	7	8	23	13	8
Th	14	3	2	13	2	4
Se	4	280	3	376	3	4
Li	0	0	0	0	0	0

Bulk chemical analysis and trace element geochemistry of specimens #1-#14

Arsenic and lead as a function of sulfur versus copper and iron for the Bisbee specimens, plotted against a comparative dataset of Kingman turquoise.

It is observed from the data table that zinc and molybdenum are consistently low for all fourteen analyses, except for the matrix analysis of the quartz conglomerate of specimen #8, which has negligible turquoise content.  A ternary diagram, which is a triangle plot that enables the use of three variables, instead of a conventional two variable X-Y scatter plot, can be used to exemplify the differences in molybdenum concentration.  This plot shows a defined pattern of Bisbee showing lead enrichment in relation to chromium versus Kingman which shows molybdenum enrichment.  Mid-grade turquoise with considerable amounts of host rock contains a significant amount of silicon, coupled with higher concentrations of potassium and sodium.  Such is indicative of higher concentrations of quartz and feldspar in the conglomerate host rock, ex. specimens #1, #2, and #9.  Specimen #11 also contains higher concentrations of silicon, representing vein turquoise in quartz.  There is an interesting correlation of copper and sodium content with grade, generally higher-grade material contains a higher copper content as expected, copper content is strongly correlated to blue saturation, with high sodium concentrations lowering the color saturation.  The high-grade specimen #3, Smoky Bisbee specimen #4, and specimen #6 have the highest copper concentrations of the specimens that were analyzed.  It is noted that specimen #5 also has a high copper content, but it contains considerably more sodium, yielding a paler coloration.  Iron concentrations are low in the specimens, apart from specimens #7, #10, and #12.  Specimen #7 contains a matrix of hematite, specimen 10 is green from iron substituted for copper in turquoise with the association of pyrite, however the iron in specimen #12 is a bit more difficult to discern.  Specimen #12 has the classic Bisbee blue look; thus, it is surprising that the iron content is so high, this specimen has been treated with a water-based epoxy hardener which undoubtedly enhanced its coloration.  Similarly, specimen #13 is epoxy stabilized, which can be noted by the lower concentrations of phosphorus and copper, without an offset balance of silicon, yielding low oxide percent totals.  Note that specimen #14 has the highest potassium content without silicon to indicate the presence of feldspar and it is absent of a silicate matrix, thus high potassium concentrations in this specimen are indicative of Zachery treatment. 

Ternary diagram showing the lead enrichment of Bisbee turquoise in specimens #1-#14 versus molybdenum enrichment in comparative Kingman specimens, in relation to chromium. 

                  The mineralogy of the Bisbee specimens is characteristic of what is expected from the chemical analyses, showing turquoise in a quartz dominant matrix.  The Smoky Bisbee specimen #4 shows more feldspar than quartz, and like specimens #5 and #6 it shows a higher turquoise content.  Specimen #5 can be differentiated from the higher-grade specimens #4 and #6, in that it has little matrix and no quartz, visually reminiscent of Sleeping Beauty.  It is noted that specimen #14 also has no quartz, also consisting almost entirely of turquoise, however, it is Zachery treated.  Adversely, specimens that are matrix dominated, consisting of quartz enriched conglomerate show varying amounts of feldspar and clay.  It is noted that the clay content increases with increasing matrix, such as specimens 2 and #9.   Specimen #9 has the highest clay concentration, coupled with the highest concentrations of orthoclase and ilmenite, showing significant alteration of the conglomerate host rock.  Iron enrichment in the specimens show a mineralogy consisting of iron oxides with an abundance of hematite and limonite.  Excessively high iron content such as specimens #7 and #10 also show a pronounced increase in pyrite, apart from the noted iron enriched specimen #12.  Iron in specimen #12 consists of limonite, with the highest limonite concentration in the specimens that were analyzed.  Again, the visual appearance and coloration, coupled with the chemical analysis, indicate that this specimen has been stabilized with a water-based hardener.  Such a treatment would enhance the color and stabilize the porosity of an otherwise undesirable stone.  The untreated coloration and hardness of specimen #12 may be comparable to the characteristics and green appearance of natural specimen #10.  Specimen #10 shows a green coloration with significant porosity and the highest hematite/pyrite content of the specimens that were analyzed.  Finally, the unusual hematite matrix of specimen #7 shows a similar mineralogy, except the matrix contains less clay and alteration than specimen #10; bound by a quartz cemented matrix.  The matrix analysis of this unusual Bisbee specimen #8 consists of greater than 70% quartz with minor feldspar and epidote.  The Glance conglomerate consists of a variation of Paleozoic sedimentary clasts, as well as Precambrian volcanics.  As such, the presence of epidote indicates a degree of metamorphism or temperature conditions indicative of volcaniclastics, within the conglomerate host rock.  Such degree of metamorphic alteration accounts for the hematite bound cement and unusual appearances of this turquoise.  High quartz content can also be coupled with minor chlorite, such as in specimens #1 and the turquoise vein in quartz of specimen #11.  The presence of chlorite indicates secondary quartz formed under different hydrothermal conditions than the quartz clasts within the conglomerate.  Such that, chlorite is an indicator to distinguish hydrothermal quartz from sedimentary clasts within the conglomerate matrix.

	#1	#2	#3	#4	#5	#6	#7	#8
Quartz	45.71	10.09	14.98	1.07	0.00	3.02	5.43	78.92
Albite	1.28	3.98	0.91	0.49	0.00	0.00	3.73	6.04
Orthoclase	2.23	4.44	1.00	1.33	0.00	1.82	0.49	0.00
Magnesiochromite	0.00	0.00	0.01	0.01	0.00	0.00	0.01	0.00
Ilmenite	0.06	0.00	0.00	0.00	0.00	0.04	0.00	0.22
Magnetite	0.50	0.02	0.00	0.00	0.41	0.49	0.00	2.18
Hematite	0.00	0.00	0.10	0.32	1.67	1.14	2.71	0.00
Rutile	0.00	0.00	0.01	0.02	0.00	0.00	0.22	0.00
Zircon	0.00	0.01	0.00	0.00	0.00	0.00	0.00	0.00
Turquoise	47.41	71.36	80.77	93.94	96.78	91.15	84.02	4.75
Ankerite	0.00	0.00	0.00	0.00	0.00	1.59	0.00	0.00
Siderite	0.00	0.00	0.00	0.00	0.00	0.09	0.00	0.00
Rhodochrosite	0.02	0.00	0.04	0.02	0.00	0.01	0.00	0.00
Azurite/Malachite	0.43	0.83	0.49	0.32	0.00	0.07	0.00	0.00
Halite	0.01	0.01	0.01	0.01	0.01	0.01	0.10	0.13
Fluorite	0.01	0.01	0.01	0.01	0.00	0.02	0.00	0.00
Anhydrite	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00
Thenardite	0.01	0.00	0.00	0.00	0.00	0.00	0.00	0.00
Barite	0.00	0.34	0.00	0.00	0.00	0.00	0.00	0.38
Pyrite	0.43	0.00	0.31	0.24	0.30	0.22	3.27	0.24
Chlorite/Serpentine	1.62	0.00	0.00	0.09	0.35	0.00	0.00	0.00
Illite/Clays	0.00	8.89	1.24	2.05	0.00	0.00	0.00	0.00
Zoisite/Clinozoisite	0.00	0.00	0.00	0.00	0.00	0.00	0.00	7.14
Chalcopyrite	0.00	0.00	0.02	0.01	0.00	0.01	0.00	0.00
Bornite	0.00	0.00	0.03	0.04	0.00	0.07	0.00	0.00
Arsenopyrite	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00
Galena	0.00	0.00	0.00	0.00	0.01	0.05	0.00	0.00
Wolframite	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00
Scheelite	0.06	0.00	0.05	0.03	0.00	0.00	0.00	0.00
Limonite/Goethite	0.21	0.00	0.00	0.00	0.44	0.20	0.00	0.00
Pyrolusite	0.00	0.03	0.00	0.00	0.01	0.00	0.01	0.00

	#9	#10	#11	#12	#13	#14
Quartz	40.56	3.61	43.92	12.93	32.96	0.00
Albite	0.00	0.87	3.98	0.00	0.00	0.00
Orthoclase	5.17	1.37	0.72	1.93	2.82	0.00
Magnesiochromite	0.00	0.02	0.00	0.00	0.00	0.00
Ilmenite	0.78	0.00	0.03	0.00	0.05	0.00
Magnetite	0.00	0.00	0.00	0.00	0.00	0.79
Hematite	0.00	3.69	0.00	2.42	0.22	0.00
Rutile	0.00	0.02	0.00	0.00	0.00	0.00
Zircon	0.04	0.00	0.00	0.00	0.00	0.00
Turquoise	36.14	86.05	46.76	75.07	61.37	95.99
Ankerite	1.67	0.00	0.00	1.86	1.54	0.00
Siderite	1.67	0.00	0.00	1.86	0.02	0.00
Rhodochrosite	0.00	0.00	0.02	0.00	0.04	0.04
Azurite/Malachite	0.94	0.00	0.36	0.00	0.54	0.33
Halite	0.01	0.01	0.01	0.01	0.01	0.01
Fluorite	0.01	0.00	0.01	0.00	0.01	0.01
Anhydrite	0.00	0.00	0.00	0.00	0.00	0.00
Thenardite	0.00	0.00	0.01	0.00	0.00	0.00
Barite	0.00	0.00	0.00	0.00	0.00	0.00
Pyrite	0.16	4.22	0.37	0.43	0.19	0.28
Chlorite/Serpentine	0.00	0.00	1.98	0.00	0.00	2.14
Illite/Clays	12.63	0.00	0.00	0.00	0.00	0.00
Zoisite/Clinozoisite	0.00	0.00	0.00	0.00	0.00	0.00
Chalcopyrite	0.00	0.00	0.00	0.00	0.02	0.02
Bornite	0.00	0.00	0.00	0.00	0.04	0.05
Arsenopyrite	0.00	0.13	0.00	0.00	0.00	0.00
Galena	0.00	0.00	0.00	0.02	0.00	0.00
Wolframite	0.00	0.00	0.02	0.00	0.00	0.00
Scheelite	0.02	0.00	0.01	0.00	0.00	0.00
Limonite/Goethite	0.03	0.00	1.81	3.41	0.16	0.34
Pyrolusite	0.18	0.01	0.00	0.07	0.00	0.00

Mineralogy of Bisbee specimens #1-#14

                  The aim of this article is to help differentiate the many varieties of Bisbee and how they differ both compositionally and mineralogically with comparisons to Kingman turquoise, which it is sometimes mistaken for.  Bisbee turquoise is uncommon and undoubtedly a lot of material still exists in unlabeled collections and hordes of vintage turquoise that are awaiting discovery.  A lot of confusion exists with identifying Bisbee turquoise, with a misconception that all Bisbee must be bright blue in color against a chocolate matrix.  Though such appearance is typical for Bisbee, it is not representative of all Bisbee turquoise.  Many types of turquoise can appear visually similar to Bisbee turquoise.  Unfortunately, provenance once lost cannot be regained, which indicates a necessity for chemical analysis.  If you are interested in the identification of origin of unknown turquoise, samples may be submitted to: West Texas Analytical Lab, 615 N. Price Rd, Pampa, TX 79065.  The testing is nondestructive and the cost is $65/specimen, plus return shipping.  I would like to thank the people who helped procure material for this research and Mike Ryan of Turquoise in America.  If you have not let purchased your copies of the three parts of Turquoise in America, it is a must-have book set for the turquoise connoisseur, detailing a considerable amount of history of turquoise mines such as Bisbee.  It is available at turquoiseinamerica.com. West Texas Analytical Laboratory is not affiliated with Turquoise in America and neither receives compensation nor benefit from the other.  The association is simply for the love of turquoise and to bridge the gap between science and history.