How do I identify Dacite?

Dacite can be identified by its hardness of 6 - 7 on the Mohs scale, Bluish-grey color. Look for these key characteristics when examining specimens.

What color is Dacite?

Dacite typically appears in Bluish-grey, brown, light to dark grey, white, yellow, etc.. Color can vary depending on impurities and formation conditions.

Dacite has a hardness of 6 - 7 on the Mohs scale. This gives it moderate hardness.

Dacite

A variety of Igneous

Uncommon

What is Dacite?

Dacite is a relatively common volcanic rock that can be found in several different hues. Ancient people sometimes used dacite in place of flint to create spears or arrowheads. The rock’s name is derived from “Dacia”, the ancient Roman province near modern Romania, where it was first described. Today, the stone is crushed and used as filler in construction projects.

Uses & Applications

Dacite can be used as a filler rock when paving and constructing roads, though it is not a popular choice due to its high silica content that may easily damage or weather. It may also be used for decorative purposes or stone carvings.

Dacite Market Value Calculator

Estimate the market value of Dacite using size, quality, and finish. This preview calculator is for quick context and is not a formal appraisal.

Dacite Localities Map

See where Dacite is found with a localities map, collecting zones, and geology context. Generate a sample map preview below.

Map preview

North ZoneCentral RidgeSouth Basin

Key Characteristics

Formation of Dacite

Dacite usually forms as an intrusive rock such as a dike or sill. Examples of this type of dacite outcrop are found in northwestern Montana and northeastern Bulgaria. Nevertheless, because of the moderately high silica content, dacitic magma is quite viscous and therefore prone to explosive eruption. A notorious example of this is Mount St. Helens in which dacite domes formed from previous eruptions. Pyroclastic flows may also be of dacitic composition as is the case with the Fish Canyon Tuff of La Garita Caldera.

Composition of Dacite

Dacite consists mostly of plagioclase feldspar with biotite, hornblende, and pyroxene (augite and/or enstatite). It has quartz as some rounded, corroded phenocrysts, or as an element of the ground-mass.