Louisiana State Mineral


Louisiana State mineral: Agate

(SiO2 )

Adopted in 1976; 2011 Re-Designated

In 1976, Louisiana adopted petrified palm wood as the official state fossil, and agate, as found in Louisiana gravel, became the state gemstone. However in 2011, (Crassostrea virginica,) oyster shell (previously agate 1976-2011) predominantly found in the waters of coastal Louisiana. was designated as Louisiana State Gemstone and agate re-designated as Louisiana State Mineral

 Louisiana State Mineral: Agate

Louisiana State mineral: Agate

Agate is a microcrystalline variety of silica, chiefly chalcedony, characterized by its fineness of grain and brightness of color. Although agates may be found in various kinds of rock, they are classically associated with volcanic rocks and can be common in certain metamorphic rocks. This might be confusing, because scientifically agate is considered a variety of the mineral quartz. Minerals are the building blocks of rocks. Agate is considered both a mineral (cryptocrystalline quartz) and a rock, and is formed by chemical precipitation from silica-rich solution in rock cavities. Agates are found within the Citronelle Formation and younger sediments in the Feliciana Parishes. Both the agate and chert originally formed within limestone that covered the central United States. Erosion released the state's gemstone from these limestones, and ancient rivers carried them into Louisiana and Mississippi.

Did you know that one of the best collecting localities for the state mineral (agate) is located close to Baton Rouge? The gravel beds along the Amite River are the primary collecting locality for the Louisiana Geological Survey.


Louisiana State mineral: Agate

The stone was given its name by Theophrastus, a Greek philosopher and naturalist, who discovered the stone along the shore line of the river while searching for algy Achates (Greek) sometime between the 4th and 3rd centuries BC. Colorful agates and other chalcedonies were obtained over 3,000 years ago from the Achates River, now called Dirillo, in Sicily.

Lore & History

Louisiana State mineral: Agate

They have been used as gemstones, talismans and amulets for thousands of years. In fact, some of the very first primitive tools were formed of agate. Such examples were found in Ethiopia that tested to being created over 2 1/2 million years ago!

The ancient Greeks believed that amulets made from agate would offer protection from accidents at sea and during Medieval times it was believed that carrying a piece of agate would attract favor from God and make the bearer more agreeable and pleasant to be around. Agates were believed to lend strength to the wearer and bring victory and protection. White agate in particular was believed to aid insomnia and to bring pleasant dreams.

Healing properties

Agates lend their aid to stomach complaints, and ailments of the colon, liver, spleen and kidneys. Placed on the body agate will also help increase circulation.

Louisiana Laws

The law designating the agate as the official Louisiana state mineral is found in the Louisiana Revised Statutes, Title 49, Section 49:163.1.

TITLE 49 - State administration
RS 49:163.1 - State mineral

§163.1. State mineral

There shall be an official state mineral. The official state mineral shall be the agate, as found in Louisiana gravel. Its use on official documents of the state and with the insignia of the state is hereby authorized.

Acts 2011, No. 232, §1.

State Rocks,
Minerals, & Gems
US State Gemstone or Gems

Gemstone, Minerals, Rocks