A trillion is a cut that has the same measurement from any flat side
to the opposing point, curved sides and rounded corners. Calibrated
stones are 3x3x3, 3.5x.3.5x3.5 usually up to about 8mm. The settings
are available in catalogues and are described this way.
Triangle stones can be equidistant or not. Catalogues have settings
for equidistant triangle stones. All catalogues have two catagories,
triangle or trillion.
I have the super secret decoder ring from Stuller, Ha! Ha!, so I
double checked the on-line catlogue that I can order from, on-line,
24/7 (something that those of you who use Rio don't seem to be able