Form

1
Form Habit

• Klein, 2002, p. 202-208

2
Form Habit

• Habit external shape of crystals
• needles acicular
• fibers
• octahedral
• prismatic

Quartz acicular
Asbestos - fibers
Quartz Prismatic habit
3
HABIT is controlled by environment of growth

• More habits
• Dendritic
• Botryoidal
• stalactitic

Manganese oxide
Aragonite, Sienna Italy
4
Form Habit

• Form Group of crystal faces, all of which have
  the same relation to the elements of symmetry and
  display the same chemical and physical
  properties, because all are underlain by the same
  geometrical arrangement.

5
Form Habit
(010)
(100)
(001)
Crystal habit of diamond This habit displays a
number of forms

• Cube with faces (100) (010) (001) FIRST FORM
• (010) (001) and (100) SECOND FORM

6
Form Habit
Open forms
Crystal faces do not enclose space
7
Form Habit
Open forms

• Prisms

8
Open forms

• Pyramids

9
Form Habit
Closed forms
All crystal faces enclose space
Dipyramids