A purple line running through the quartz, with amethyst druzy through the centre.
Purple in quartz needs iron present while the crystal is growing. A distinct line of it means the iron came and went: present for that interval, absent either side of it, then back again by the time the central druzy formed. The clear quartz between is the gap.
The back and base are cemented and the outside painted dark, standard for cut geodes. The crystal itself is untouched.
Mineral: Amethyst, the purple variety of quartz (SiO₂)
Crystal system: Trigonal
Origin: Brazil
Hardness: 7 on the Mohs scale; hard, though individual crystal tips chip easily
Treatment: None to the amethyst. Backing, base and exterior are cemented and painted, standard practice for cut geodes
Dimensions: 11 x 19 x 34.5 cm
Weight: 10.65 kg Note: Keep it out of direct sunlight. Sustained UV breaks down the iron centres that produce the purple, and amethyst that fades does not come back
You will receive the exact piece photographed.