naturally occurring optical phenomenon

MIRAGE
List of words for the clue naturally occurring optical phenomenon from the crossword:
REM SNOW ORGANIC INHERENT STAGED RAREST PETROLEUM OBSIDIAN MADE ION EOLITH DISTORTION ABERRATION RAINBOW POLARIZATION POLARISATION PHI IMAGE FRINGE
WordClue
EVENTphenomenon
FIBERoptical or nerve
LASERoptical device
CAMERAoptical device
BOILINGbulk phenomenon
RAINBOWoptical phenomenon
CROWDINGvisual phenomenon
OBSIDIANnaturally occurring volcanic glass
PERISCOPEoptical device
PETROLEUMnaturally occurring flammable liquid
PROJECTORoptical device
TELESCOPEoptical device
WHIRLWINDweather phenomenon
BINOCULARSoptical device
MICROSCOPEoptical device
SLIPSTREAMfluid dynamics phenomenon
THEODOLITEoptical device
REFRACTOMETERoptical device
PETROLEUMnaturally occurring flammable liquid
OBSIDIANnaturally occurring volcanic glass