Texas Rock Identification Marble

Picture identification guide for polished stones and tumbled rocks.

Texas rock identification marble.

Identifying how the marble was made will tell you the most about its history and whether it has any value. In the rock identification charts on pages 40 41 the texas rocks described in this book are arranged in four major groups according to their texture. It is composed primarily of the mineral calcite caco 3 and usually contains other minerals such as clay minerals micas quartz pyrite iron oxides and graphite. Authentic marble is a metaphoric rock formed by applying heat to limestone forming crystals of calcite a relatively soft mineral.

Llanite is a rock found in texas and a few other locations that contains tiny euhedral well formed crystals of blue quartz in a groundmass of pink and brown feldspar. It is used in jewelry figurines sculptures. Llanite a beautiful gem quality type of granite with sky blue quartz inclusions. Because of this the surface of marble shows scratches and wear.

How to use the rock identification charts. Like the state capitol is made of texas pink granite. Trying to identify a marble may make you well lose your marbles. Sometimes it can be nearly impossible to positively id a particular marble but there are ways you can narrow the possibilities.

Marble is a metamorphic rock that forms when limestone is subjected to the heat and pressure of metamorphism. Glassy the rocks are smooth dark and shiny 2. Named after llano the only place where it is found. Although commonly called gray granite these specimens are technically diorite also see numbers 64 and 70 through 73.

They are usually brown to gray in color and may have fossils and water or wind marks. In the mason texas area topaz is most if not always found in the streeter grit and katemcy areas which is in the central west to south western side of the county. Texas red and and pink granite is widely used for the antiquity of monument and building material. Topaz is commonly associated with silicic igneous rocks of the precambrian granite which is where the topaz is in mason county texas.

Most popular are red and pink varieties but many shades of gray are also quarried for architectural and monument use. Topaz was first recognized in mason county in 1904. Another form of crystalline calcite. Sedimentary rocks such as limestone or shale are hardened sediment with sandy or clay like layers strata.

Zebra marble is a black and white material that has a coloration similar to a zebra. Photographs and information for a large collection of igneous metamorphic and sedimentary rocks.