Banding isn’t so much the issue anyway. Look at Carnelian, which
might be a solid color. If it’s banded it’s Sardonyx. Carnelian is
Agate. Agate is Chalcedony.
I think most consumers know “Agate”, and less know “Chalcedony”. At
least I find myself explaining it all the time. Traditionally it’s
chalcedony if it’s colorless or blue, but that is changing to
include lavender, purple, pink, green and even Orange. In that last
case it’s a case of renaming something that already has a name:
Carnelian! And Green Chalcedony is either Chrysoprase or Plasma. So,
It really does not matter if it’s Agate or Chalcedony anyway. No one
should be coming down on you for being wrong unless they really have
a sad home life.
Side note: Ellensburg Blue Agate is Chalcedony. Even though it is
blue, it’s still acceptable to call it “Agate”.
So, if it’s transparent or translucent and has no color, than it’s
chalcedony.
If it’s Orange, it’s either.
If it’s blue it might be either.
Anything else is agate, unless it if Opaque. Then it’s Jasper.
Unless it’'s opaque and translucent. Then it’s Jasper-Agate.
You could play it safe and just call it “cryptocrystalline quartz”.
No one can argue that point!