COVELLITE - Perhaps a very good topic to discuss.
A copper mineral that is poorly understood.
Here is a breakdown of different types of copper
with percentage content of copper. Primary Sulfides Minerals Chalcopyrite CuFeS2 34.6
Bornite Cu5FeS4 63.3
Secondary Minerals Supergene Sulfides Chalcocite Cu2S 79.9
Covellite CuS 66.5 Native Copper Metal Cu 100.0
Carbonates Malachite CuCO3.Cu(OH)2 57.5
Azurite 2CuCO3.Cu(OH)2 55.3
Hydroxy-silicates Chrysocolla CuO.SiO2.2H2O 36.2
Hydroxy-Chlorides Atacamite
Cu2Cl(OH)3 59.5
Oxides Cuprite Cu2O 88.8
Tenorite CuO 79.9
Sulfates Antlerite CuSO4.2Cu(OH)2 53.7
Brochantite CuSO4.3Cu(OH)2 56.2
COVELLITE COPPER Covellite (also known as covelline) is a rare copper sulfide mineral
with the formula CuS Ace Aris Tech report - PAGE - 191 mentions
2 mystery metals - one being yellow and the other a
grey -
SUPPOSE THE MYSTERY - GREY MINERAL - IS COVELLITE
WHAT IF THE GREY MINERAL... OXIDIZED - TURNED TO - BLUE + PURPLE ? ARIS REPORT - PAGES - 199 - 205
IS COVELLITE HARD TO DETECT ? Covellite is known to form in weathering environments in surficial deposits where copper is the primary sulfide.[10] As a primary mineral, the formation of covellite is restricted to hydrothermal conditions, thus rarely found as such in copper ore deposits or as a volcanic sublimate Covellite form superstructures.
As described for copper monosulfides like pyrite, the assignment of formal oxidation states to the atoms that constitute covellite is deceptive.[6] The formula might seem to suggest the description Cu2+, S2−. In fact the atomic structure shows that copper and sulfur each adopt two different geometries.
However photoelectron spectroscopy, magnetic, and electrical properties all indicate the absence of Cu2+ (d9) ions.[6] In contrast to the oxide CuO, the material is not a magnetic semiconductor but a metallic conductor with weak Pauli-paramagnetism.[7] Thus, the mineral is better described as consisting of Cu+ and S− rather than Cu2+ and S2−. Compared to pyrite with a non-closed shell of S− pairing to form S22−, there are only 2/3 of the sulfur atoms held.[6] The other 1/3 remains unpaired and together with Cu atoms forms hexagonal layers reminiscent of the boron nitride (graphite structure).[6] Thus, a description Cu+3S−S22− would seem appropriate with a delocalized hole in the valence band leading to metallic conductivity. Subsequent band structure calculations indicate however that the hole is more localized on the sulfur pairs than on the unpaired sulfur. This means that Cu+3S2−S2− with a mixed sulfur oxidation state -2 and -1/2 is more appropriate.
Despite the extended formula of Cu+3S2−S2− from researchers in 1976 and 1993, others have come up with variations, such as Cu+4Cu2+2(S2)2S2.[8][9] READ MORE - https://en.wikipedia.org/wiki/Covellite LET'S NOW ASK.... Under a spectrometry lense would a lab assayor or instrument - MISS - the indifferent bond of this covellite copper - simply OVERLOOK or misidentify it as a - sulphur atom ? KEEP IN MIND...
covellite formes a super structure - even in layering - and let's keep in mind,
the original lab assays peformed tests with - nitric acids and Hydrochloric.
SULPHURIC ACID - is the acid to use for such a - covellite copper.
COVELLITE GREY - wikipedia 
PAGE 199 - 205 ACE ARIS REPORT Shows several pictures of abluish purple mineral -
LINK - https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=2ahUKEwjR5MPdlYD0AhVKk2oFHUpzAE8QFnoECAgQAQ&url=http%3A%2F%2Faris.empr.gov.bc.ca%2FArisReports%2F24286.PDF&usg=AOvVaw3kDAe26GpeGJhC9I0WDpBN SUPERB INTEL ON COVELLITE COPPER - https://open.library.ubc.ca/media/download/pdf/24/1.0166616/1 Wango Comment - I would think a retake on assaying these petrographic rock samples would be
more than appropriate taking into consideration that the - bule purple mineral -
that is quite evident yet no mention of with in the - tech report.
Iron + Sulphur No values were reported.
These are two very important minerals that coreract with copper and should have been documented in order to better understand the dynamics of what mineral interactions might ve occuring. And of course, a retake using sulphuric acids and fully understanding the complex structures of the covellite atomic structures -
Cheers....