Fireplaces, Heating Stoves, Flues and Chimneys - fire resistant material (brick or glass)

Hi -
I am looking for a brick that I can can use inside a fireplace. Or a heat-resistant one-way mirror that I can use on one side of a fireplace that is shared by two rooms, and I need privacy in one of them.

Any suggestion greatly appreciated.
Thanks!

Is it possible to go with a fireplace screen on one side so you can block the view?

I'm not a mason, but use white fire brick made to go inside the firebox of a fireplace only if you want to close it off permanently.
Tempered glass is the only kind that should be used (such as in fireplace glass doors) with a fireplace, but you can see through them.
You might be able to spray the outside of glass doors with high-heat black BBQ grill paint to prevent see-through, and then you would still be able to open it when you wanted to.
This would be the most economical way, and fireplace door sets are very easy to install (just four bolts tightened to the inside of the fireplace).
Check with your local Building Inspector for local code on this before doing anything.
Good luck!
Mike

Hello
Keep in mind any changes you make inside the fire box will keep the fire place from working right...you may want to go to a gas log and work from there...I would not recomend any changes inside the fire place with any think...Good luck