Definition
Pumice is a volcanic rock that consists of highly vesicular rough textured volcanic glass, which may or may not contain crystals
Trachyte is a grey fine-grained volcanic rock which mainly consists of alkali feldspar
History
Origin
Spain
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Discoverer
Unknown
Alexandre Brongniart and René Just Haüy
Etymology
From Old French pomis, from a Latin dialect variant of pumex
From Greek trakhus rough’ or trakhutēs roughness
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Medium Hardness Rock
Family
Group
Volcanic
Volcanic
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock