IT’S TIME FOR...
CRYSTALLOGRAPHY
TRIVIA!!
Rules
Three rounds
 10 questions per round
 Pass answers to team to
right for grading

Round 1 – Question 1
What is the term to describe a
crystal that displays
imperfectly developed crystal
faces?
Round 1 – Question 2
Mineral symmetry is manifest by external
symmetry of single crystals and by
internal symmetry of atomic
arrangement.
What is the main difference between
external and internal symmetry
elements?
Round 1 – Question 3
What are the four types of external
symmetry operations? (must know all
four)
Round 1 – Question 4
Two-fold roto-inversion is equivalent to
what other symmetry operation
Round 1 – Question 5
What is the HermanMaugin notation for the
symmetry operations
shown here?
Round 1 – Question 6
Which is the proper
Point Group label
(Herman–Maugin
notation) for the
symmetry operations
shown to the left?
4mm 4/m2/m2/m
4/m2/m 422
Round 1 – Question 7
How many crystal classes (point groups)
are possible to describe external
symmetry?
Round 1 – Question 8
Rank the six major crystal systems in
order of increasing symmetry.
Isometric
Monoclinic
Triclinic
Orthorhombic Tetragonal Hexagonal
Round 1 – Question 9
The point group
4/m32/m
belongs to what
crystal system?
Round 1 – Question 10
The crystal class
(point group) 2/m
symmetry shown here
belongs to what
crystal system?
End of Round 1
Pass your answers to the team on your
right for grading.
Round 1 – Question 1
What is the term to describe a
crystal that displays
imperfectly developed crystal
faces?
Subhedral
Round 1 – Question 2
Mineral symmetry is manifest by external
symmetry of single crystals and by
internal symmetry of atomic arrangement.
What is the main difference between
external and internal symmetry elements?
Internal Symmetry involves translation,
external symmetry does not
Round 1 – Question 3
What are the four types of external
symmetry operations? (must know all
four)
Rotation
Reflection (or Mirrors)
Center of Symmetry
Roto-Inversion
Round 1 – Question 4
Two-fold roto-inversion is equivalent to
what other symmetry operation
Mirror Plane
Round 1 – Question 5
What is the HermanMaugin notation for the
symmetry operations
shown here?
422
Round 1 – Question 6
Which is the proper
Point Group label
(Herman–Maugin
notation) for the
symmetry operations
shown to the left?
4mm 4/m2/m2/m
4/m2/m 422
Round 1 – Question 7
How many crystal classes (point groups)
are possible to describe external
symmetry?
32
Round 1 – Question 8
Rank the six major crystal systems in
order of increasing symmetry.
Triclinic
Monoclinic
Orthorhombic
Tetragonal
Hexagonal
Isometric
Round 1 – Question 9
The point group
4/m32/m
belongs to what
crystal system?
Isometric
Round 1 – Question 10
The crystal class
(point group) 2/m
symmetry shown here
belongs to what
crystal system?
Monoclinic