Lead glass is a type of glass in which lead replaces the calcium content of a typical potash glass.  It contains typically 18–40% lead oxide by weight while modern lead crystal (known as flint glass), historically contains a minimum of 24%.

Lead glass benefits from high clarity and scratch resistance but its unique quality is its absorption of radiation. Glasses like Shotts RD30™, RD50™ and RS series are typically used in a wide range of applications in the medical and nuclear industries – for example in x-ray facilities.