Rocks: Granite & Marble Overview

Study Notes

Colour: A range of colours, including black, grey, pink, and cream
Texture: Coarse grained
Formation: An intrusive rock formed when molten magma pushes its way into the Earth's crust, cools, and hardens under the surface. The slow cooling process creates large crystals, including quartz, feldspar, and mica.
Use: Used in everyday products like kitchen countertops due to its hardness and durability.
Example: Found in the Mourne Mountains, Ireland.
Key characteristic: Intrusive rock formed below the surface of the Earth.

Colour: White, red, green, or black
Texture: Smooth
Formation: Formed when limestone is exposed to intense heat or pressure, often by geological occurrences like movement of tectonic plates and magma contact.
Use: Used to create monuments, floor tiles, fireplaces, and other decorative items.
Examples: Found in County Antrim (white), County Cork (red), Connemara (green), County Galway (green) and County Kilkenny (black).
Permeability - A characteristic that allows water to pass through.

Colour: White or grey
Texture: Granular (grainy)
Formation: Formed when sandstone is subjected to great heat or pressure due to plate movement, or contact with molten magma.
Use: Used in counter tops, road chippings, and glass production. High hardness makes it durable.
Examples: Croagh Patrick in County Mayo and the Great Sugarloaf in County Wicklow.
Key characteristic: A metamorphic rock that is extremely hard.

Colour: Reddish/brown
Texture: Coarse grained
Formation: Formed from sand that has been transported and deposited in layers, eventually compressed and cemented together by pressure.
Use: Common building material and used in patios.
Examples: Found in MacGillycuddy's Reeks in County Kerry and the Galtee Mountains in the south of Ireland.

Colour: Grey
Texture: Coarse grained
Formation: Formed from the accumulated deposits of shells and skeletons of marine creatures, compressed, cemented and hardened over millions of years in shallow seas.
Characteristic: Permeable and soluble.
Use: Used for monuments, buildings, and cement production.
Example: Limestone landscapes in the Burren, Ireland are a significant tourist attraction.

Colour: Grey/black
Texture: Medium grained
Formation: An extrusive rock formed when lava cools and hardens on the Earth's surface after volcanic activity. The quick cooling process results in small, virtually invisible crystals.
Use: Road chippings due to its hardness. The landscape formations (like the Giant's Causeway) are a popular tourist destination.
Example: Found in the Antrim-Derry Plateau, in particular the Giant's Causeway.