A while back I covered diamond rifle sights, and recently I became aware that Trijicons “Bright & Tough” night sights use a sapphire crystal to focus light into the tritium lamp.
Pretty cool. The Brownells description of the night sights:
Nighttime and low light shooting tests prove sights equipped with these glowing dots are easier to see and more accurate than instinctive shooting with standard black sights. Rugged, heavy duty, Traser®, luminous, 3-Dot tritium lamps provide their own long-lasting energy source. Lamps are mounted in silicone-sealed, metal cylinders to give maximum protection from breakage or leakage. Polished sapphire, crystal windows give a bright, crisp and perfectly round aiming dot in low light. Inlaid white rings around each sapphire make the sights appear as standard white dots in daylight. Very narrow blades do not have the white ring and will look more like a plain black blade in daylight. Most can be installed in factory dovetail or sight base. Glock® models require use of special Trijicon installation tools to prevent sight damage.
I do not know the MSRP but Brownells have them listed for $99 – $145 depending on the handgun model.
[ I make no money what-so-ever from linking to Brownells and have no business relationship with them. ]