Daniel Dennett identifies four properties that are commonly ascribed to qualia. According to these, qualia are:

ineffable; that is, they cannot be communicated, or apprehended by any other means than direct experience.
intrinsic; that is, they are non-relational properties, which do not change depending on the experience’s relation to other things.
private; that is, all interpersonal comparisons of qualia are systematically impossible.
directly or immediately apprehensible in consciousness; that is, to experience a quale is to know one experiences a quale, and to know all there is to know about that quale.

i read a book from this guy awhile ago; i can’t remember the name but i know i liked it. consciousness explained? i should try to find my old notes on it.