Green grape agate

English
Prehnite

Origin
Australia

Introduction
The chemical composition of prehnite is Ca₂Al(AlSi₃O₁₀)(OH)₂, belonging to silicate minerals. It is commonly found in the secondary veins of basalt or granite and is also known as the "dream stone" or "spiritual stone."

In the 18th century, Dutch Colonel Hendrik von Prehn first brought this mineral back to Europe and was the first to name a mineral after himself. In European history, it has often been regarded as a gem for collection and meditation, and was considered by royalty and nobles to be a stone that enhances intuition and offers protection.