Pumice
Definition/Function:
Pumice is natural volcanic glass filled with gas bubbles or fractured into small
fragments of jagged glassy foam. It is
the result of molten rock being ejected from the volcano before the rock can
recrystallize. Its jagged form makes it a
good candidate for a mild abrasive. It is considered a "mild" abrasive because its
hardness is below that of most metals.
Significance in the Environment:
Characteristic Features:
Pumice is isotropic with a refractive index in the range of 1.48 to 1.53. It often
contains bubbles or a jagged shape
resulting from the fracturing of surface bubbles of gas. These bubbles are often very
elongated as a result of the
explosive ejection of this volcanic glass from the volcano.
Associated Particles:
References: