Granodiorite is less known and used igneous rock falling in intrusive type. It is akin to granite in look but containing a high percentage of plagioclase (K & Ca-rich) feldspar so looks off-white in color.
Granodiorite is in section 4 of the QAPF diagram.
Physical Properties of Granodiorite
|Grain size||Medium to Coarse-Grained|
|Luster||Grainy, pearly, & vitreous|
|Compressive strength||175.00 N/mm2|
|Specific heat capacity||0.79 KJ/Kg K|
|Resistance||Heat & wear-resistant|
Mineralogy of Granodiorite
It contains less than 20% Quartz. Other minerals are plagioclase, which is always greater than 2/3 of total feldspar. The plagioclase is with lesser orthoclase, Biotite, and amphibole (hornblende). It has Silica (SiO 2) content – 63%-69%.
- It is felsic to intermediate in mineral content.
- It is an intrusive igneous rock.
- It has a large amount of sodium and calcium in plagioclase.
- It has potassium feldspar, some quartz, and a bit of muscovite mica.
- Biotite & amphiboles give it a two-toned but darker look.
- Mica found in hexagonal crystals while hornblende found in needle-like crystals.
- Magnetite, limonite, ulvospinel like oxide minerals, as well as some sulfide minerals are present in it.
Formation of Granodiorite
It formed by the intrusion of silica-rich magma that eventually cools in stocks or batholiths below the earth surface. It exposes after uplift or erosion of the upper continental crust. The entire process takes place in three major steps, melting of magma, shifting, and solidification.
- The causes of melting are mainly an increase in temperature, reduction in pressure, or chemical changes.
- Shifting could be intrusive means within the earth crust or extrusive out of the earth surface.
- Solidification may form with crystallization that ends with crystalline or granular rocks. If it is without crystallization, it ends with natural glasses.
Granodiorite is intrusive types of igneous rocks. Therefore, the magma cools slowly within the earth crust and resulting in coarse-grained rocks.
Occurrence of Granodiorite
Granodiorite is the result of fractional melting of a mafic parent rock, which takes place above a subduction zone. Thereby, it mainly found in volcanic arcs and cordilleran mountain building. For instance, when subduction takes place along the edge of a continent like it happened with the Andes Mountains. You can see that it emplaces in large batholiths, which are used to running for thousands of square miles. It eventually sends magma to the surface to produce composite volcanoes with andesite lavas.
According to Wikipedia.
- The erratic glacial boulder of Granodiorite is found in Plymouth Rock of the USA.
- A large deposit exists in the Sierra Nevada Mountains of the States of America.
- A big quarry was found at Mons Claudianus located in the Red Sea Governorate in Eastern Egypt.
- In New Zealand, some minor deposits found in Northland and the Coromandel Peninsula, west Nelson area, Westland, Fiordland, and Stewart Island.
- It found in Loda Pahar area of Bundelkhand in a massive deposit.
Uses of Granodiorite
It has limited applications in the construction industry.
- Due to high silica content, it is not ideal as aggregates mixing in cement concrete, but useful in other applications as crushed stone for road building.
- It resembles granite a lot, so it is good as dimensional stones for exterior applications like paving for patios, paths, and even pool deck.
- It is ideal as ornamental stone thanks to its Rosetta stone-like appearance. Thereby, it is a better choice for facing, foyers, and porches.
- The portico columns of the Pantheon in Rome are formed from single shafts of Granodiorite. Each shaft is 12 meters tall by 1.5 meters in diameter.
Who Will Provide You Granodiorite?
World of Stones USA is an ideal destination to obtain natural stones for exterior applications. Now, we know Granodiorite is a choice for exterior applications and some industrial usages as the crushed stones. You will find the best quote, top quality, and excellent service as well as perfect guidance in consulting at the World of Stones and its distributors existing nearby you.