Definition
Dacite is a volcanic igneous rock which is rintermediate in composition between andesite and rhyolite
Trachyte is a grey fine-grained volcanic rock which mainly consists of alkali feldspar
History
Origin
Romania and Moldova, Europe
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Discoverer
Unknown
Alexandre Brongniart and René Just Haüy
Etymology
From Dacia, a province of the Roman Empire which lay between the Danube River and Carpathian Mountains where the rock was first described
From Greek trakhus rough’ or trakhutēs roughness
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Medium Hardness Rock
Family
Group
Volcanic
Volcanic
Other Categories
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock