n this specimen of chalcedony we can observe, when light passes through it, the presence of a cavity partially filled with water of crystallization. This water was trapped in the process of formation of the geode, millions of years ago. A mineralogical curiosity.

Stalactitic aggregate, pineapple shape, of amethyst quartz crystals. Brilliant and with a more intense "amethyst" color at the tips of the crystals. An aesthetic piece, common, but aesthetic... It belongs to the Joan Astor collection (Barcelona), with a handwritten label and typewritten box.

On a matrix formed by good size crystals of quartz (var. amethyst) some scalenohedral calcite crystals are disposed, brilliant and translucent. Calcite presents intense red fluorescence under LW-UV light. A very aesthetic piece that represent the calcite crystals which appear in the classic Brazilian amethyst geodes.