Basalt Granite And Obsidian Rock

Obsidian is a very shiny natural volcanic glass.

Basalt granite and obsidian rock.

Molten rock material below the surface is called magma. Appearance of basalt is dull and soft and that of obsidian is shiny. Basalt is a dark colored fine grained igneous rock composed mainly of plagioclase and pyroxene minerals. The hardness of basalt is 6 and that of obsidian is 5 5 5.

It most commonly forms as an extrusive rock such as a lava flow but can also form in small intrusive bodies such as an igneous dike or a thin sill it has a composition similar to gabbro the difference between basalt and gabbro is that basalt is a fine grained rock while. Properties of rock is another aspect for basalt vs obsidian. Dacite is an extrusive igneous rock. Magma that has reached the surface is lava.

The principle minerals that make up dacite are plagioclase quartz pyroxene or hornblende. When obsidian breaks it fractures with a distinct conchoidal fracture. Associate each rock name granite diorite gabbro rhyolite andesite basalt obsidian pumice scoria tuff and volcanic breccia from the classification chart with the geological setting numbers 1 12 shown on the following diagram. Obsidian is volcanic glass meaning it has no crystals and consists primarily of silica with just enough impurities to color it whereas basalt is a low silica high iron magnesium igneous rock entirely made of small crystals of various minerals including plagioclase feldspar and usually pyroxene and or amphibole.

The canadian shield of north america contains huge outcroppings surface rocks of granite. Basalt is available in black brown light to dark grey colors whereas obsidian is available in black blue brown green orange red tan yellow colors. Gabbro andesite pegmatite basalt pumice porphyry obsidian granite and tuff. Basalt is an extrusive or intrusive rock that makes up most of the world s oceanic crust.

Igneous rocks from left to right.