Scintillating is an adjective. The adjective is the word that accompanies the noun to determine or qualify it.

Is scintillating a verb or adjective?

Scintillate means to be sparkling and lively. Scintillate has its roots in the Latin words scintillare, meaning "to sparkle," and scintilla, meaning "a spark." The verb scintillate is related to the adjective scintillating and the noun scintilla.

Is usually is an adverb?

The adverb usually refers to what typically or normally happens. We use it mostly in mid position, between the subject and the main verb, or after the modal verb or first auxiliary verb, or after be as a main verb: Children usually enjoy visits to the zoo.