The bands are in there. The camera keeps missing them.
Agate Pyramid
A polished agate pyramid, milky white with a broad apricot zone through one face and nested concentric bands that only show up in the right light. Held against something dark the pale areas turn faintly blue, which is light scattering off silica fibers too small to see rather than any blue mineral being present.
This piece gets a price when it is ready to sell.
- Size
- about 2 inches across the base
- Hardness
- Mohs 6.5-7
- Crystal system
- trigonal
- Family
- banded chalcedony
- Luster
- waxy to greasy
- Streak
- white
- Cleavage
- none
The listing
The bands are the reason this is an agate rather than plain chalcedony, and they are also the hardest thing about it to photograph. In most light the stone reads as a soft apricot-into-white gradient. Turn it until the light rakes across the face and nested arcs appear, following the wall of the cavity the silica grew into, one layer at a time.
The blue is a separate trick. Chalcedony is quartz grown as fibers packed too finely to resolve, and that structure scatters short wavelengths the way the atmosphere does. Put the pyramid on black and it goes blue. Put it on white and the blue vanishes. Nothing about the rock changed.
