Crystal only works on a ceiling when two things meet: cut facets and a point source behind them. That pairing is what produces the sparkle a crystal ceiling light is bought for. Put a flat opal LED panel behind the same crystal and you have paid for expensive glass that does nothing.
Lead crystal contains lead oxide, which makes it heavier, softer and deep-cuttable, and that deep cut is what splits light into the rainbow flecks you see thrown on a wall. Lead-free K9 glass is the common modern choice — close to the same brilliance, lighter, and far less fragile in transit. Acrylic droplets weigh least of all and suit a ceiling rose that cannot carry much load, but they sparkle less and they scratch.
A hanging chandelier needs headroom that most modern rooms simply do not have. A flush crystal ceiling light of 15-25 cm build height gives the same glitter without anyone ducking, which is why it is the usual answer in hallways, bedrooms and on landings. Keep the chandelier for a stairwell or a room of 2.7 m and up.
Clear, small, E14 candle or golfball lamps. The tighter the glowing point, the sharper the reflections; a frosted lamp erases the effect almost entirely. Stay at 2,700 K, which matches the warm cast of cut glass, and fit a dimmer — with crystal, dimming is the whole difference between festive and glaring.
Almost always a frosted lamp. Swap it for a clear candle or filament lamp and the reflections come back.
It refracts more strongly. K9 is lighter and tougher, which matters when the fitting hangs from plasterboard.
Less than the lamp count suggests — cut glass scatters output sideways. Treat it as decorative and add a second layer if the room is a working one.
Where the ceiling is high enough to hang something, see the chandeliers.
