By Chisom Ibemere
Llanite is a unique and rare variety of volcanic rock, which is found only within a comparatively small area in Llano County, Texas, USA.
It was first discovered in the year 1940 and the name Llanite was derived from the region in which it was discovered, Llano County in Texas.
Llanite is a type of igneous rock that widely occurs in the Llano igneous province of central Texas in the United States.
The area where it occurs is relatively small, and the only known outcrops of Llanite are situated on private land and are hence not accessible to the public.
Llanite is not a popular or well-known or widely-used rock material. It is too rare and mostly difficult to extract in large enough quantities for use as building stone, and it also have little or no significant industrial applications.
However, minute quantities of Llanite can be found in rock and mineral collections, and they are sometimes used for decorative purposes, such as for making gemstone or lapidary items.
Llanite is composed mainly of blue-grayish plagioclase feldspar, with smaller amounts of quartz and biotite.
Its characteristic blue variegated color is probably due to the presence of small spherules of blue-gray quartz and blue-gray feldspar within the rock. Llanite typically has a fine-grained texture, is hard and dense, and has a relatively high compressive strength.
Llanite is relatively rare and occurs in only one small area of Texas, its global value is comparatively modest. It is mostly used for decorative or collector purposes, it is not a particularly well-known material or widely sought after in the global market.