Blue Basalt Blocks

Gabbro is coarse grained while basalt is fine grained. Gabbro is sometimes called “black granite” for it too is coarse-grained, but a large proportion of iron-bearing minerals make gabbro heavier and dark colored. Gabbro can also be gray or light green. Granite is a coarse-grained igneous rock with average grain size ranging from 1 to 25 millimeters. Gabbro is generally coarse grained, with crystals in the size range of 1 mm or greater. Therefore, Gabbro is a dense, mafic intrusive rock closer to granite than basalt.

Basalt is used as crushed aggregate in construction projects. Crushed basalt is used for road base, concrete aggregate, asphalt pavement aggregate, railroad ballast, filter stone in drain fields. But, basalt is also cut into dimension stone. In thin slabs it is used for building veneers, flooring, pavers, countertops, stairs, mosaic, gravestones, etc.

All natural stones are porous to some extent, which means they may absorb liquids and moisture if exposed. Basalt is one of the denser natural stones, as compared to a material like sandstone but can still absorb unwanted contaminants over time.

Lava Stone is a more generic term than Basalt from a geological standpoint. This stone generally cools less rapidly than basalt, making the grain not quite as fine and not as dense. But it would be useful to know that, the stones called Lava Stones are more porous, lighter and fragile.

Bluestone is not a geological term and does not fall within any distinct category such as igneous, sedimentary or metamorphic. Bluestone is a generic name for several rock types typically used in the landscape industry, however most bluestone is actually limestone which is soft. Bluestone is used to name light gray basalt stones in some countries because of its color, but in some other countries it is a hard sedimentary stone compared to a type of basalt.Basalt is formed when lava cools at a fast rate, usually gray to black in color and very hard and dense.Lava rock is a generic term to describe molten lava that has cooled slowly to create igneous rock. But as it is generally used in the stone market, lava stone is much more porous.So all “Basalt, Lava Stone, Bluestone” really are different rocks.