What is a dacite rock?

Dacite, volcanic rock that may be considered a quartz-bearing variety of andesite. Dacite is primarily associated with andesite and trachyte and forms lava flows, dikes, and sometimes massive intrusions in the centres of old volcanoes.

What is the texture of dacite rock?

Dacite ( /ˈdeɪˌsaɪt/) is a volcanic rock formed by rapid solidification of lava that is high in silica and low in alkali metal oxides. It has a fine-grained (aphanitic) to porphyritic texture and is intermediate in composition between andesite and rhyolite.

How do you identify lava rocks?

Lava can explode out of a volcano and make pumice or ash, or flow down its side and make thick layers of fine grained rock or volcanic glass. Distinguishing Characteristics: Very fine grained, pinkish-grey, sometimes with dark streaks.

What kind of rock is dacite associated with?

Join Britannica’s Publishing Partner Program and our community of experts to gain a global audience for your work! Dacite, volcanic rock that may be considered a quartz-bearing variety of andesite. Dacite is primarily associated with andesite and trachyte and forms lava flows, dikes, and sometimes massive intrusions in the centres of old volcanoes.

What kind of feldspar is found in dacite?

The feldspar content of dacite ranges from oligoclase to andesine and labradorite; sanidine occurs also in some dacites and when abundant gives rise to rocks transitional to the rhyolites.

Which is the correct specific gravity of dacite?

Streak is the color of rock when it is crushed or powdered. The streak of Dacite is white whereas its fracture is conchoidal. Luster of Dacite is the interaction of light with the surface of Dacite. Luster of Dacite is subvitreous to dull. Dacite cleavage is perfect. The specific gravity of Dacite is 2.86-2.87.

How is dacite used in the construction industry?

Viscous dacite magmas with little to no gas can extrude from a vent to produce thick lava flows or slowly build a steep volcanic dome atop of the vent. Dacite is sometimes used to produce crushed stone. It performs well as fill and as a loose aggregate in a wide variety of construction projects.

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