|Pseudonym reading||む ん む ん さ ん|
|Specified type||Prefecture designation|
|Type||Natural monuments and geological minerals|
|Designated date||March 19, 1965|
|location||Ichinoseki City Daitocho Chokai-Ku Maehata|
Corundum is a steel ball, which is second only to diamonds, and it is called a ruby (red) or sapphire (blue), which is as beautiful and beautiful as a gem, and is prized as a gem.
Corundum in Daito Town, Ichinoseki City, is black or rarely dark blue and does not become a gem.
The geology of the Daibato area Maebata district in Ichinoseki city is composed of the paleostrati and granodiorite intruded in it, and the corundum is a roughly north-south spreading horn fes (contact) generated by contact alteration of limestone and granodiorite It is produced in metamorphic rock).
Corundum is contained in the form of hexagonal and plate-like crystals in this rock, and many have a diameter of 3 mm or less and a thickness of 1 mm or less, sometimes reaching 10 mm in diameter and 3 mm in thickness.
Although corundum is sometimes produced in granitic granite and as sandstone, it is extremely rare to be produced in hornfels, and it is rare that many large grains are contained, and it is scientifically valuable. is there.