Hobbies And Interests
History
Oya is a type of volcanic, mineral rock compressed of volcanic ash, also known as oya tuff. It has been used extensively throughout Japan for building stones and sculptures. Quarried in a mine located in Oya, Japan, it has been used as an engineering material for the past 1,000 years because of its advantage of being cut easily.
Mineralogy
Oya in mineral form is caused by a low grade metamorphism of zeolite clay, or changing of the clay's physical structure. It takes 50 to 5,000 years and around 100 degrees Fahrenheit for the change to happen. Because the oya tuff is exposed to other natural minerals, the zeolite maybe compressed with other minerals, such as quartz.
Facts
Oya is a brittle and porous mineral containing volcanic rock fragments. The oya-ishi rock is flat,angular and structured in a horizontal pattern. These minerals have a linear texture, much like that of wood grain. When left unexposed, oya has a bluish green color that turns to black when exposed to daylight.