A scintillator composition comprising a garnet represented by (M1-x-yNxAy)3(Al5-a-bCaDb)O12, where M comprises yttrium, or terbium, or gadolinium, or holmium, or erbium, or thulium, or ytterbium, or lutetium, or combinations thereof, where N comprises additives including a lanthanide, or an alkali metal, or an alkaline earth metal, or combinations thereof, where A comprises a suitable activator ion including cerium, or europium, or praseodymium, or terbium, or ytterbium, or combinations thereof, where C or D comprises lithium, or magnesium, or gallium, or an element from group IIIa, or IVa, or Va, or IIId transition metal, or IVd transition metal, or combinations thereof, where x ranges from about 0 to about 0.90, y ranges from about 0.0005 to about 0.30, and a sum of a and b ranges from about 0 to 2.0.