The crystal look

Crystal body tone sits at the transparent end of the opal spectrum. The stone isn't white or black — it's clear to translucent, the way sea glass is clear. Light passes through the body rather than reflecting off it. You can sometimes see the bench through the stone. The play-of-color you see is lit from inside, which gives it a different character than the surface flash you get from a white stone.

This piece is Ethiopian Welo crystal — the slight lavender tint in the body is typical of this material. The blue and green fire is visible through the translucent mass from multiple angles at once, not just the top face. That's the tell: crystal opal shows color in three dimensions. Rotate it and different zones light up. The whole interior is active.

What it looks like cut

A well-cut crystal cab in this material glows rather than flashes. The play-of-color shifts smoothly as you tilt it — no hard edges, no distinct color zones that wink on and off. The transparency of the body means the cab can be thinner than a white stone cab and still show the color fully. More light reaches the color bar; more of it gets diffracted back out. What you lose in opacity you gain in depth.