What type of stone is this?

[sbrack61]

I acquired 3 of these at an estate sale and have not been able to identify what they are.

[Sef20]

Dyed Tiger Eye Quartz

[GemWise]

Looks like a cats eye tourmaline to me. “Wavy-gravy” eye!

[nytenspro]

Synthetic

[jbergman]

http://www.jtv.com/library/glass-cats-eye-facts.html

[OpalBali]

Agree. Heated and changed the colour of quartz tiger eye.

[jbergman]

This is man-made glass, not heated natural tiger’s-eye