1
ESS 101 B Laboratory 6 Quiz: Metamorphic
Rocks Actual Exam 2026/2027: Questions and
Answers | 100% Pass for Geology Success – Pass
Guaranteed - A+ Graded
Section 1: Metamorphic Rock Identification (10 questions)
Q1: This metamorphic rock specimen
shows very fine-grained texture with excellent planar cleavage that allows it to split into thin, flat
sheets. The surface appears dull and low-luster. It does not react with dilute HCl acid.
A. Phyllite
B. Slate [CORRECT]
C. Schist
D. Gneiss
Correct Answer: B
Rationale: Slate is characterized by very fine-grained texture and perfect slaty cleavage, which
is the lowest grade of foliation in metamorphic rocks. The dull luster distinguishes it from
phyllite, which has a silky sheen. Slate forms from the low-grade regional metamorphism of
shale or mudstone (protolith). Schist would show visible micas and higher luster, while gneiss
would display coarse-grained banding. The lack of acid reaction rules out marble, and the
foliation distinguishes it from non-foliated rocks like quartzite.
,2
Q2: This rock specimen
displays fine-grained foliation with a distinct silky or satin-like luster on the foliation surfaces. It
shows wrinkled or crinkled cleavage surfaces and is slightly coarser than slate but finer than
schist.
A. Slate
B. Phyllite [CORRECT]
C. Mica Schist
D. Slate (high grade)
Correct Answer: B
Rationale: Phyllite represents intermediate-grade metamorphism between slate and schist,
characterized by phyllitic luster—a silky sheen caused by very fine-grained muscovite and
chlorite aligned parallel to foliation. The key diagnostic feature is this satin-like sheen combined
with fine grain size, distinguishing it from the dull slate below it and the visibly micaceous schist
above it in the metamorphic sequence. The protolith is typically shale or mudstone that has
undergone more intense metamorphism than slate but less than schist.
, 3
Q3:
This specimen shows medium- to coarse-grained texture with abundant visible platy minerals
(micas) creating a glittery appearance. Large, red to black equidimensional crystals
(porphyroblasts) are scattered throughout the finer-grained matrix. The rock exhibits strong
planar foliation.
A. Gneiss
B. Phyllite
C. Schist [CORRECT]
D. Amphibolite
Correct Answer: C
Rationale: This is a classic garnet-mica schist displaying schistosity—defined by the parallel
alignment of visible platy minerals (biotite and muscovite). The large garnet crystals are
porphyroblasts that grew during metamorphism within the foliated matrix. Schist represents
medium-grade metamorphism of pelitic (clay-rich) protoliths. Gneiss would show compositional
banding rather than just mineral alignment, phyllite would be finer-grained with silky rather than
glittery luster, and amphibolite would be dominated by amphibole minerals rather than micas.
ESS 101 B Laboratory 6 Quiz: Metamorphic
Rocks Actual Exam 2026/2027: Questions and
Answers | 100% Pass for Geology Success – Pass
Guaranteed - A+ Graded
Section 1: Metamorphic Rock Identification (10 questions)
Q1: This metamorphic rock specimen
shows very fine-grained texture with excellent planar cleavage that allows it to split into thin, flat
sheets. The surface appears dull and low-luster. It does not react with dilute HCl acid.
A. Phyllite
B. Slate [CORRECT]
C. Schist
D. Gneiss
Correct Answer: B
Rationale: Slate is characterized by very fine-grained texture and perfect slaty cleavage, which
is the lowest grade of foliation in metamorphic rocks. The dull luster distinguishes it from
phyllite, which has a silky sheen. Slate forms from the low-grade regional metamorphism of
shale or mudstone (protolith). Schist would show visible micas and higher luster, while gneiss
would display coarse-grained banding. The lack of acid reaction rules out marble, and the
foliation distinguishes it from non-foliated rocks like quartzite.
,2
Q2: This rock specimen
displays fine-grained foliation with a distinct silky or satin-like luster on the foliation surfaces. It
shows wrinkled or crinkled cleavage surfaces and is slightly coarser than slate but finer than
schist.
A. Slate
B. Phyllite [CORRECT]
C. Mica Schist
D. Slate (high grade)
Correct Answer: B
Rationale: Phyllite represents intermediate-grade metamorphism between slate and schist,
characterized by phyllitic luster—a silky sheen caused by very fine-grained muscovite and
chlorite aligned parallel to foliation. The key diagnostic feature is this satin-like sheen combined
with fine grain size, distinguishing it from the dull slate below it and the visibly micaceous schist
above it in the metamorphic sequence. The protolith is typically shale or mudstone that has
undergone more intense metamorphism than slate but less than schist.
, 3
Q3:
This specimen shows medium- to coarse-grained texture with abundant visible platy minerals
(micas) creating a glittery appearance. Large, red to black equidimensional crystals
(porphyroblasts) are scattered throughout the finer-grained matrix. The rock exhibits strong
planar foliation.
A. Gneiss
B. Phyllite
C. Schist [CORRECT]
D. Amphibolite
Correct Answer: C
Rationale: This is a classic garnet-mica schist displaying schistosity—defined by the parallel
alignment of visible platy minerals (biotite and muscovite). The large garnet crystals are
porphyroblasts that grew during metamorphism within the foliated matrix. Schist represents
medium-grade metamorphism of pelitic (clay-rich) protoliths. Gneiss would show compositional
banding rather than just mineral alignment, phyllite would be finer-grained with silky rather than
glittery luster, and amphibolite would be dominated by amphibole minerals rather than micas.
