When sourcing crystal prisms, the primary distinction lies in the lead content and manufacturing process. High-end projects should prioritize K9 optical glass or Full Lead Crystal (over 30% lead oxide) for maximum refractive index and 'rainbow' light dispersion. Ensure the prisms are machine-cut and polished rather than mold-pressed, as machine-cutting guarantees sharp facets and superior light refraction. Always request a transmittance report to verify the absence of bubbles, scratches, or a yellowish tint.