chalcopyrite

Lookalike discrimination

Record which observations distinguish the candidate from pyrite, bornite or gold and which remain ambiguous.

1. Which fresh-surface, hardness or density observations support chalcopyrite over the named alternatives? measurement
2. Were those observations made on the candidate grain, its coating or the surrounding matrix? boundary

Chemical and structural agreement

Require agreement between the identified phase and the scale and limitations of its analytical evidence.

1. Do grain-resolved chemistry and diffraction support chalcopyrite, and what uncertainty or competing phases remain? measurement
2. What evidence threshold permits confirmed identity for this intended use? definition

Chalcopyrite contribution

Establish the measured phase fraction and the basis for attributing copper to it.

1. What chalcopyrite fraction was measured, on what mass, volume or area basis? measurement
2. Which other copper-bearing phases prevent assigning the entire copper assay to chalcopyrite? boundary

Accessible chalcopyrite

Record grain sizes, enclosing phases and exposed boundaries at a stated observation scale.

1. Which minerals enclose or intergrow with chalcopyrite, and at what grain sizes? measurement
2. What separation or sampling action is justified by the observed liberation? action

Tarnish or treatment

Keep observed surface features separate from unsupported explanations of their origin.

1. What cleaning, chemical treatment, polishing or storage exposure is documented? provenance
2. Does examination beneath the coating identify chalcopyrite, another mineral or an unresolved substrate? measurement

Alteration boundary

Locate surviving chalcopyrite and distinguish it from separately identified products.

1. What evidence distinguishes a thin surface film from replacement extending into the grain? boundary
2. What observed change warrants revised storage, isolation or further analysis? action

Origin and association

Record the documented origin and relationships needed to interpret the observed chalcopyrite.

1. Is the material naturally collected, experimentally produced or of unknown origin, and what record supports that attribution? provenance
2. Which host and mineral-contact observations are direct evidence, and which origin interpretations remain hypotheses? boundary

Claim-supporting sample

Relate each identity, abundance or condition judgment to the material actually examined.

1. How were grains or particles selected, and could selection favour conspicuous or unaltered chalcopyrite? provenance
2. Does the evidence describe one grain, one specimen or a representative population? boundary

Proportionate mineral testing

Balance diagnostic value against loss of crystals, coatings and mineral-contact evidence.

1. Can imaging or analysis of an existing fragment resolve the uncertainty before scratching, sectioning or grinding? action
2. Which chalcopyrite faces, intergrowths or alteration boundaries must the selected action preserve? boundary

Sample-specific processing response

Require measured response and characterization of the tested feed before recommending a processing route.

1. What recovery or dissolution was measured for this chalcopyrite-bearing material under documented conditions? measurement
2. What additional characterization of associated phases, generated dust or residues is needed before the proposed trial? action

Kinds and varieties

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

• hypogene chalcopyrite in porphyry copper systems
• volcanogenic massive sulfide (VMS) chalcopyrite
• skarn and carbonate-replacement chalcopyrite
• sediment-hosted / stratiform copper chalcopyrite
• epithermal and vein chalcopyrite
• supergene-altered / tarnished chalcopyrite
• bornite-chalcopyrite solid-solution / high-temperature intermediate solid solution (iss)
• massive sulfide vs disseminated chalcopyrite ore

1. Which of these kinds and varieties hold for the sense of chalcopyrite this model covers, and on what evidence? provenance

Identifiers and schemes

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

• Wikidata - Q31646 - item for chalcopyrite as a mineral species
• IMA mineral name - Chalcopyrite - grandfathered IMA-CNMNC species; nickel-strunz 2.CB.10a

1. Which of these identifiers and schemes hold for the sense of chalcopyrite this model covers, and on what evidence? provenance

Standards and regulation

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

• IMA-CNMNC: approved mineral species name and formula CuFeS2
• UN GHS / OSHA HazCom: copper concentrates containing chalcopyrite classified for metal-dust and SO2 smelter emissions rather than as a distinct product standard

1. Which of these standards and regulation hold for the sense of chalcopyrite this model covers, and on what evidence? provenance

Real-world use

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

• Dominant copper ore mineral, concentrated by froth flotation then smelted/converted to blister copper and electrorefined
• Source of by-product gold, silver, molybdenum, and sometimes rhenium in porphyry systems
• Minor use as a specimen mineral and, historically, as a brass-yellow decorative stone (often confused with pyrite)

1. Which of these real-world use hold for the sense of chalcopyrite this model covers, and on what evidence? provenance

Typical measurements

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

• Cu grade in chalcopyrite-bearing ore - 0.3-2.0 (porphyry); 1-5+ (VMS/skarn concentrates) - wt% Cu
• Mohs hardness - 3.5-4 - Mohs
• Specific gravity - 4.1-4.3 - g/cm3

1. Which of these typical measurements hold for the sense of chalcopyrite this model covers, and on what evidence? provenance

Failure modes and hazards

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

• Acid mine drainage: oxidation of chalcopyrite (with pyrite) generates sulfuric acid and dissolved copper
• SO2 and slag hazards in smelting of chalcopyrite concentrates
• Misidentification as gold (fool's gold confusion, though pyrite is the usual culprit)

1. Which of these failure modes and hazards hold for the sense of chalcopyrite this model covers, and on what evidence? provenance

Regional variation

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

• Ore naming: 'yellow copper ore' / Kupferkies (German) / chalcopyrite vs copper pyrites in older British usage
• Metallurgical practice differs: flash smelting vs heap bioleaching of chalcopyrite (latter is kinetically slow)

1. Which of these regional variation hold for the sense of chalcopyrite this model covers, and on what evidence? provenance

Neighbouring kinds and how to tell them apart

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

• pyrite (FeS2) - Pyrite is paler brass-yellow, harder (Mohs 6-6.5), cubic, and does not give a greenish-black streak with a copper tint; chalcopyrite is deeper yellow, Mohs ~3.5-4, and often tarnishes iridescent.
• gold - Gold is malleable, denser (~19 g/cm3), and does not powder; chalcopyrite is brittle, SG ~4.2, and yields a greenish-black streak.
• bornite (Cu5FeS4) - Fresh bornite is brownish-bronze and typically tarnishes to peacock purple; chalcopyrite stays brassy yellow until secondary tarnish; chemistry and XRD distinguish them.

1. Which of these neighbouring kinds and how to tell them apart hold for the sense of chalcopyrite this model covers, and on what evidence? provenance