Mineralogy_Single Crystal Habits Flashcards
Long and needle-like, thinner than prismatic but thicker than
fibrous
Acicular
Elongated and flattened like a blade of grass. More elongated
than platy and thinner than tabular
Bladed
Rectangular and box-like, but not necessarily with flat sides. More
elongated than equant but less elongated than prismatic and thicker
than tabular
Blocky
Any three perpendicular axis through the crystal are more or less
equal. Can be used to describe rounded as well as angular crystals.
Fluorite forms crystals that are a good example of equant crystals.
Equant
Thinner than acicular crystals in either individual crystals or in a
tight compact almost cloth-like mass.
Fibrous
Flattened and thin crystals (like plates) but wider than bladed
and thinner than tabular
Platy
occur when a crystal stops growing and then
for some reason continues to grow.
Phantomed
One of the most common of crystal habits. Are
“pencil-like”, elongated crystals that are thicker than needles.
Prismatic
(which mean false shape in Latin) is a crystal that
has replaced another mineral’s chemistry or structure with its own
without changing the outward shape of the original mineral.
Pseudomorphs
occur when a crystal stops growing and then
for some reason continues growth on the upper portion of the crystal
but not the lower portion.
Sceptered
Slightly more elongated than equant but not as elongated as
prismatic and possibly more rounded than blocky
Stubby
Book-like (tablets) that are thicker than platy but not as
elongated as bladed.
Tabular
