A lot of the orca agate on the market is dyed. This piece is not. No dye, no bleach.
That sentence carries more weight here than on almost anything else we sell, because the pattern that makes this material recognisable, hard black against clean white, is exactly what dye and bleach are used to exaggerate. Collectors have been raising it publicly for a while and the answers from most sellers are thin. On a trade name only a few years old, with no established grading and heavy demand, that is the predictable outcome.
Colour treatment on banded chalcedony is genuinely difficult to spot once done. So the answer cannot be a photograph, it has to be a supply chain someone will put their name to.
Mineral: Chalcedony (silicon dioxide, SiO₂), banded, so agate
Crystal system: Trigonal
Origin: Madagascar
Hardness: 6.5 to 7 on the Mohs scale; durable, though the polished surface will dull if knocked about
Treatment: None
Dimensions: 7.2 x 4.48 x 9.56 cm
Weight: 430 g
You will receive the exact piece photographed.