Australian Prehnite.

Prehnite is a mineral belonging to the silicate group and is primarily composed of aluminum, calcium, and silicon. Its chemical formula is Ca2Al(AlSi3O10)(OH)2·H2O. This stone is known for its crystalline structure and its wide range of colors, ranging from pale green to green-yellow, yellow, and sometimes golden.
Prehnite has an orthorhombic crystalline structure and belongs to the orthorhombic crystal system. Its crystals are often found in massive formations and botryoidal crystals. It exhibits a vitreous or waxy luster on its surface.
Prehnite is named after Hendrik von Prehn, a Dutch colonel who first discovered it in 1788 in South Africa, but it has since been found in many other parts of the world, including Australia, the United States, China, and various locations in Africa. It is often associated with minerals such as epidote, calcite, and zeolite.