Amethyst druzy through the centre, with a purple band crossing the quartz.
That band is a record of timing. Purple needs iron present while the crystal grows, so a line of it means the iron arrived, stopped, and came back later for the druzy at the centre. The clear quartz either side of the band is the interval when there was none.
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: 13 x 10 x 17 cm
Weight: 6.85 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.