Beautiful celestine with large crystals and great color

A celestine geode from Madagascar with unusually large individual crystals and an intense light blue color.

Celestine is strontium sulfate (SrSO₄). The light blue color is caused by traces of radiation defects in the crystal lattice, a rare color in the mineral kingdom.

What distinguishes this geode is the size of the individual crystals. Instead of the usual fine-tipped distribution, significantly larger celestine prisms have grown here, indicating particularly slow, undisturbed crystallization conditions in the cavity.

Celestine is soft with a Mohs hardness of 3-3.5 and should be protected from scratches. Prolonged UV radiation can fade the color.

A collector's item with clear mineralogical depth.