Home

lawsonite

Lawsonite is a hydrous calcium aluminum sorosilicate mineral with the chemical formula CaAl2Si2O7(OH)2·H2O. It crystallizes in the monoclinic system and forms elongated to tabular crystals that commonly occur as inclusions in metamorphic rocks. The mineral is colorless to pale blue or greenish and has a vitreous to pearly luster.

Geologically, lawsonite is relatively rare and forms under high-pressure, low-temperature conditions typical of subduction zones. It

Significance in metamorphic petrology arises from its stability field, which constrains pressure–temperature paths for subduction-related rocks.

Lawsonite was named in honor of the American geologist Andrew Lawson. It has been reported from blueschist

is
a
characteristic
mineral
of
blueschist
facies
and
is
frequently
found
with
minerals
such
as
glaucophane,
zoisite,
epidote,
and
chlorite.
Its
presence
in
a
rock
indicates
a
history
of
subduction-zone
metamorphism
and
the
involvement
of
significant
transported
water
in
the
mineral
assemblage.
Lawsonite
can
dehydrate
during
metamorphism,
releasing
water
and
driving
subsequent
reactions
in
the
surrounding
mineral
assemblage.
and
related
metamorphic
rocks
in
various
parts
of
the
world,
including
North
America,
Europe,
and
Asia.