The Stop Button emoji is a solid coloured square. This button is used to completely stop all sound activities whether out of your own initiative or someone else’s. If you stop your own music, you probably either got bored of listening or wanted some quiet time.
The stop button emoji was introduced in 2014 and released as part of the Unicode 11.0 standard. This emoji can be found under the symbols
category. Because the stop button emoji has been around for quite some time, it should display correctly in the majority of operating systems.