brilliant
/ˈbril-yənt/
adjective
very bright : glittering
striking, distinctive
distinguished by unusual mental keenness or alertness
a brilliant light
bright brilliant radiant luminous lustrous mean shining or glowing with light. bright implies emitting or reflecting a high degree of light. brilliant implies intense often sparkling brightness. radiant stresses the emission or seeming emission of rays of light. luminous implies emission of steady, suffused, glowing light by reflection or in surrounding darkness. lustrous stresses an even, rich light from a surface that reflects brightly without glittering.
noun
a gem (such as a diamond) cut in a particular form with numerous facets so as to have special brightness or brilliance