How do you identify genuine chrysoberyl?

Real chrysoberyl is most often recognised by its really tough hardness, around 8.5 on the Mohs scale, plus a refractive index somewhere near 1.746–1.755, and also frequently by that bright, silvery chatoyant stripe in the cat’s-eye type; it shows up along the line of movement.

Since it is ranked as the third-hardest usual natural gemstone, chrysoberyl can take a striking polish, and it keeps razor-sharp facet edges for a long while. For the identification of the sought-after “cymophane” cat’s-eye variant, gemmologists check for the well-known “milk and honey” look beneath a single light source; that specific optical effect is hard for synthetic look-alikes to mirror in an authentic way.