Looks eye clean under bright light.  Certified colorless spinel no heat treatment.  Very rare material.  Spinel is far more rare than sapphire or ruby and colorless is rarely seen at the mines in Sri Lanka where this stone was purchased.  Under torch light and magnification there are slight inclusions present under the crown and a veil like inclusion was noted.  Si quality under magnification.  Nice cutting job on this with lots of internal reflection. This stone would make an attention getter ring because of how it would stand out in any light and the size for a clear no color stone.
Video taken in shaded light.  Photos inside light.
Certified gem with no heat treatment.  Natural earth mined in Sri Lanka.