All about copper minerals

B. Chalcopyrite

The principal ore of copper, mined globally from porphyry copper deposits, is:
A. Sphalerite
B. Chalcopyrite
C. Galena
D. Pyrite

A. CuFeS₂

The chemical formula of Chalcopyrite is:
A. CuFeS₂
B. Cu₂S
C. FeS₂
D. Cu₂CO₃(OH)₂

B. Porphyry copper deposit

Chalcopyrite is the most abundant ore mineral in which type of deposit?
A. Banded iron formation
B. Porphyry copper deposit
C. Lateritic nickel deposit
D. Placer gold deposit

A. Hardness

In hand specimen, Chalcopyrite is often mistaken for Pyrite. The best field test to distinguish it is:
A. Hardness
B. Magnetic property
C. Taste test
D. Effervescence in HCl

A. Greenish black

The streak of Chalcopyrite, which helps in identification, is:
A. Greenish black
B. Yellow brown
C. Reddish brown
D. White

D. Calcite

Which of the following is NOT a typical associate of Chalcopyrite in hydrothermal sulfide deposits?
A. Pyrite
B. Sphalerite
C. Galena
D. Calcite

A. Sulfides

Chalcopyrite belongs to which mineral group?
A. Sulfides
B. Sulfates
C. Carbonates
D. Oxides

A. Chalcopyrite

The brassy-yellow copper-iron sulfide mineral that tarnishes to an iridescent purple or blue is:
A. Chalcopyrite
B. Bornite
C. Covellite
D. Marcasite

A. Porphyry copper

Which major copper deposit type is usually mined for Chalcopyrite in the Philippines (e.g., Philex, Atlas, Tampakan)?
A. Porphyry copper
B. Epithermal gold
C. Lateritic nickel
D. VMS (volcanogenic massive sulfide)

A. Pyrite

The brassy appearance of Chalcopyrite makes it easy to confuse with “Fool’s Gold,” which is:
A. Pyrite
B. Magnetite
C. Ilmenite
D. Hematite

B. Cu₂S

The chemical formula of Chalcocite, an important copper ore, is:
A. CuFeS₂
B. Cu₂S
C. Cu₅FeS₄
D. CuCO₃·Cu(OH)₂

B. Sulfides

Chalcocite is classified under which mineral group?
A. Sulfates
B. Sulfides
C. Oxides
D. Carbonates

B. Steel-gray to black

The typical color of fresh Chalcocite is:
A. Brass-yellow
B. Steel-gray to black
C. Deep red
D. Blue to purple

Which copper ore mineral is a major product of supergene enrichment in porphyry copper deposits?
A. Chalcocite
B. Sphalerite
C. Magnetite
D. Cassiterite

A. Chalcocite

Which copper ore mineral is a major product of supergene enrichment in porphyry copper deposits?
A. Chalcocite
B. Chalcopyrite
C. Bornite
D. Covellite

B. More copper

Compared to Chalcopyrite, Chalcocite contains:
A. Less copper
B. More copper
C. No copper
D. Equal copper

B. More copper

Compared to Chalcopyrite, Chalcocite contains:
A. Less copper
B. More copper
C. No copper
D. Equal copper

B. Supergene enrichment zone

Chalcocite commonly forms in which ore zone?
A. Oxidation zone
B. Supergene enrichment zone
C. Primary magmatic zone
D. Placer deposits

C. It enriches ore grades up to 3–5% Cu

In porphyry copper systems, Chalcocite is especially important because:
A. It indicates early hydrothermal mineralization
B. It is the main gangue mineral
C. It enriches ore grades up to 3–5% Cu
D. It is only found in placer deposits

C. CuS

The chemical formula of Covellite is:
A. CuFeS₂
B. Cu₂S
C. CuS
D. Cu₅FeS₄

B. Sulfides

Covellite belongs to which mineral group?
A. Oxides
B. Sulfides
C. Carbonates
D. Silicates

B. Indigo-blue with metallic sheen

The typical color of Covellite is:
A. Brass-yellow
B. Indigo-blue with metallic sheen
C. Steel-gray to black
D. Deep red

C. Supergene enrichment zone

Covellite is most commonly formed in which zone of ore deposits?
A. Primary magmatic zone
B. Oxidation zone
C. Supergene enrichment zone
D. Placer deposits

C. Lead-gray to black

The streak of Covellite is:
A. Yellow
B. Shiny black
C. Lead-gray to black
D. White

B. Less copper

Compared to Chalcocite, Covellite contains:
A. More copper
B. Less copper
C. No copper
D. Equal copper

B. Indigo-blue iridescent color

Covellite’s diagnostic property is its:
A. Blood-red streak
B. Indigo-blue iridescent color
C. Hardness of 7
D. Strong magnetism

C. Cu₅FeS₄

The chemical formula of Bornite is:
A. Cu₂S
B. CuFeS₂
C. Cu₅FeS₄
D. CuS

B. Sulfides

Bornite belongs to which mineral group?
A. Oxides
B. Sulfides
C. Silicates
D. Carbonates

B. Brownish-bronze

The fresh color of Bornite is typically:
A. Steel-gray
B. Brownish-bronze
C. Indigo-blue
D. Brass-yellow

A. Peacock Ore

Due to its iridescent tarnish of purple, blue, and red, Bornite is commonly known as:
A. Peacock Ore
B. Ruby Copper
C. Cogwheel Ore
D. Iceland Spar

B. Hypogene copper sulfide deposits and supergene enrichment zones

Bornite is most commonly found in:
A. Supergene zones only
B. Hypogene copper sulfide deposits and supergene enrichment zones
C. Sedimentary manganese deposits
D. Chromite seams

C. Grayish-black

The streak of Bornite is described as:
A. Greenish-black
B. Shiny black
C. Grayish-black
D. Brownish-black

A. Sulfosalts

Tetrahedrite belongs to which mineral group?
A. Sulfosalts
B. Sulfides
C. Carbonates
D. Silicates

B. Steel-gray to iron-black

The typical color of Tetrahedrite is:
A. Brass-yellow
B. Steel-gray to iron-black
C. Indigo-blue
D. Brownish-bronze

B. Brownish-black

The streak of Tetrahedrite is:
A. Yellow
B. Brownish-black
C. Red
D. Greenish-black

B. Hydrothermal veins

Tetrahedrite is commonly associated with which type of deposit?
A. Porphyry copper deposits
B. Hydrothermal veins
C. Banded iron formations
D. Lateritic nickel deposits

B. Less copper and more antimony

Compared to Chalcopyrite, Tetrahedrite contains:
A. No antimony
B. Less copper and more antimony
C. More copper and no iron
D. Only sulfur and oxygen

C. Fahlores group

Tetrahedrite is sometimes referred to as a member of the:
A. Arsenopyrite group
B. Galena group
C. Fahlores group
D. Pyroxene group

A. Gold-bearing epithermal veins in Lepanto and Surigao

In Philippine deposits, Tetrahedrite has been reported in association with:
A. Gold-bearing epithermal veins in Lepanto and Surigao
B. Porphyry copper deposits in Benguet
C. Chromite seams in Zambales
D. Manganese nodules in offshore Cagayan

B. Cu₉S₅

The chemical formula of Digenite is:
A. Cu₂S
B. Cu₉S₅
C. CuFeS₂
D. Cu₅FeS₄

B. Sulfides

Digenite belongs to which mineral group?
A. Sulfosalts
B. Sulfides
C. Oxides
D. Carbonates

B. Steel-blue to bluish-gray

The typical color of Digenite is:
A. Indigo-blue
B. Steel-blue to bluish-gray
C. Brass-yellow
D. Brownish-bronze

C. Blue-black

The streak of Digenite is:
A. Yellow
B. Lead-gray to black
C. Blue-black
D. Brownish-black

B. Supergene enrichment zones in copper deposits

Digenite is commonly associated with which deposit zone?
A. Hypogene magmatic deposits
B. Supergene enrichment zones in copper deposits
C. Oxidized gossan zones
D. Placer deposits

B. Lower copper content

Compared to Chalcocite, Digenite contains:
A. Higher copper content
B. Lower copper content
C. Equal copper content
D. No copper content

C. Chalcocite

Digenite is commonly intergrown with which other copper sulfide mineral?
A. Magnetite
B. Chalcopyrite
C. Chalcocite
D. Galena

B. Cu₂CO₃(OH)₂

The chemical formula of Malachite is:
A. Cu₂S
B. Cu₂CO₃(OH)₂
C. CuFeS₂
D. Cu₃AsS₄

B. Carbonates

Malachite belongs to which mineral group?
A. Sulfides
B. Carbonates
C. Silicates
D. Oxides

B. Green

The typical color of Malachite is:
A. Brass-yellow
B. Green
C. Indigo-blue
D. Brownish-bronze

B. Green

The streak of Malachite is:
A. White
B. Green
C. Blue-black
D. Brownish-black

B. Supergene enrichment zone

Malachite most commonly forms in which deposit zone?
A. Hypogene magmatic deposits
B. Supergene enrichment zone
C. Oxidized zone of copper deposits
D. Placer deposits

C. Azurite

Malachite is often associated with which other secondary copper mineral?
A. Chalcopyrite
B. Chalcocite
C. Azurite
D. Bornite

C. Green banded masses and botryoidal forms

A distinctive feature of Malachite is:
A. Brass-yellow metallic tarnish
B. Blue iridescence
C. Green banded masses and botryoidal forms
D. Strong magnetism

B. Cu₃(CO₃)₂(OH)₂

The chemical formula of Azurite is:
A. Cu₂CO₃(OH)₂
B. Cu₃(CO₃)₂(OH)₂
C. Cu₂S
D. Cu₅FeS₄

C. Carbonates

Azurite belongs to which mineral group?
A. Sulfides
B. Silicates
C. Carbonates
D. Oxides

B. Deep -blue

The typical color of Azurite is:
A. Bright green
B. Deep -blue
C. Steel-gray
D. Brownish-bronze

A. Blue

The streak of Azurite is:
A. Blue
B. Green
C. Black
D. White

B. Oxidized zone of copper deposits

Azurite most commonly forms in which deposit zone?
A. Hypogene magmatic zone
B. Oxidized zone of copper deposits
C. Supergene sulfide zone
D. Placer deposits

B. Blue crystals and massive habit

A diagnostic property of Azurite is:
A. Green botryoidal form
B. Blue crystals and massive habit
C. Strong magnetism
D. Blood-red streak

A. Cu₂O

The chemical formula of Cuprite is:
A. Cu₂O
B. Cu₂S
C. Cu₃(CO₃)₂(OH)₂
D. Cu₂CO₃(OH)₂

B. Oxides

Cuprite belongs to which mineral group?
A. Sulfides
B. Oxides
C. Carbonates
D. Silicates

C. Red to dark red

The usual color of Cuprite is:
A. Bright green
B. Deep azure-blue
C. Red to dark red
D. Black metallic

C. Brownish-red

The streak of Cuprite is:
A. Blue
B. Green
C. Brownish-red
D. Black

B. Oxidized zone of copper deposits

Cuprite is most commonly found in which deposit zone?
A. Hypogene zone
B. Oxidized zone of copper deposits
C. Supergene sulfide enrichment zone
D. Placer deposits

A. Ruby copper

Cuprite is also known by what common name?
A. Ruby copper
B. Cobalt bloom
C. Fool’s copper
D. Peacock ore

A. CuO

The chemical formula of Tenorite is:
A. CuO
B. Cu₂O
C. Cu₂S
D. Cu₃(CO₃)₂(OH)₂

B. Oxides

Tenorite belongs to which mineral group?
A. Sulfides
B. Oxides
C. Carbonates
D. Silicates

A. Black

The streak of Tenorite is usually:
A. Black
B. Red
C. Green
D. Blue

B. Oxidized zone of copper deposits

Tenorite most commonly occurs in:
A. Hypogene zone
B. Oxidized zone of copper deposits
C. Supergene sulfide enrichment zone
D. Alluvial placer deposits

A. Melaconite

Tenorite is also referred to as:
A. Melaconite
B. Ruby copper
C. Peacock ore
D. Cobalt bloom

B. CuSiO₃·2H₂O

The chemical formula of Chrysocolla is:
A. Cu₂O
B. CuSiO₃·2H₂O
C. CuCO₃·Cu(OH)₂
D. CuO

A. Silicate

Chrysocolla belongs to which mineral group?
A. Silicate
B. Oxide
C. Sulfide
D. Carbonate

B. Blue to green

The characteristic color of Chrysocolla is:
A. Bright red
B. Blue to green
C. Black
D. Yellow-brown

B. Supergene oxidized zones of copper deposits

Chrysocolla is usually found in:
A. Primary hypogene copper zones
B. Supergene oxidized zones of copper deposits
C. Alluvial placer deposits
D. Nickel laterite profiles

A. (Cu,Fe)₁₂As₄S₁₃

The chemical formula of Tennantite is:
A. (Cu,Fe)₁₂As₄S₁₃
B. (Cu,Fe)₁₂Sb₄S₁₃
C. Cu₅FeS₄
D. Cu₃AsS₄

B. Sulfosalt

Tennantite belongs to which mineral group?
A. Sulfide
B. Sulfosalt
C. Oxide
D. Carbonate

B. Black to dark gray

The streak of Tennantite is generally:
A. Green
B. Black to dark gray
C. Red
D. White

B. Hydrothermal veins with copper sulfides

Tennantite is most commonly found in:
A. Oxidized zones of copper deposits
B. Hydrothermal veins with copper sulfides
C. Lateritic nickel deposits
D. Placer gold deposits

B. Arsenic

Tennantite is a significant source of which metal besides copper?
A. Zinc
B. Arsenic
C. Lead
D. Cobalt

A. Polymetallic veins

In the Philippines, Tennantite is most likely found in:
A. Polymetallic veins
B. Chromite bodies
C. Nickel laterites
D. Sand and gravel deposits

D. CuSiO₃·OH

The chemical formula of Dioptase is:
A. CuSiO₃·2H₂O
B. Cu₆Si₆O₁₈·6H₂O
C. CuSiO₃·H₂O
D. CuSiO₃·OH

C. Silicate

Dioptase belongs to which mineral group?
A. Oxide
B. Sulfide
C. Silicate
D. Carbonate

A. Bright emerald-green

The typical color of Dioptase is:
A. Bright emerald-green
B. Blue to sky-blue
C. Black to gray
D. Red to brown

A. Supergene oxidized copper zones, especially in arid regions

Dioptase most commonly occurs in:
A. Supergene oxidized copper zones, especially in arid regions
B. Hypogene massive sulfide deposits
C. Placer deposits with native copper
D. Porphyry intrusions at depth

A. White to greenish

The streak of Dioptase is:
A. White to greenish
B. Blue
C. Black
D. Red

B. Emerald

Dioptase is often mistaken for which mineral?
A. Malachite
B. Emerald (Beryl)
C. Azurite
D. Chrysocolla

A. Cu₃AsS₄

The chemical formula of Enargite is:
A. Cu₃AsS₄
B. (Cu,Fe)₁₂As₄S₁₃
C. Cu₂S
D. Cu₅FeS₄

B. Sulfosalt

Enargite belongs to which mineral group?
A. Sulfide
B. Sulfosalt
C. Oxide
D. Carbonate

A. Hydrothermal veins

Enargite is most commonly found in:
A. Hydrothermal veins and high-sulfidation epithermal deposits
B. Oxidized copper zones
C. Nickel laterite deposits
D. Placer deposits

A. Lepanto (Mankayan, Benguet)

A notable Philippine deposit where Enargite is abundant is:
A. Lepanto (Mankayan, Benguet)
B. Surigao nickel laterite
C. Zambales chromite
D. Masbate epithermal gold

A. Arsenic

Enargite is an important ore of copper and also contains:
A. Arsenic
B. Antimony
C. Zinc
D. Lead

C. Lepanto Mine (Benguet)

The mineral Luzonite was first discovered in which Philippine mine?
A. Philex Mine (Benguet)
B. Atlas Mine (Cebu)
C. Lepanto Mine (Benguet)
D. Silangan Mine (Surigao)