Placing turntable on top of fireplace mantle?

My room doesn't have a ton of space, my fireplace mantle is very solid and stable, and it does not get hot to the touch (have tested this already)

Any negatives to placing it here? Previously I was using a wall shelf, (pictured in the second and third pictures), but placing it on the mantle would take up even less space in the room. Just wondering if I will have any additional vibrations which could cause reduction in sound quality by using the mantle instead of my old wall shelf.

See pictures (note I just moved so things are a mess and not set up yet):

Looks good, except for the chimney. When you see the word "chimney" think great big tuning fork going through the roof picking up every vibration from wind, rain, etc. Not saying its bad just think about it, nowhere near as good as it might seem. Still, a good solid base probably better than most racks. Replace the turntable cones with springs, preferably Townshend Pods, and you should have the best of both worlds- stable base, isolation from structure-borne vibration.
Is that an active fire place, do you use it? That corner and a TT it is really gonna collect the bass? Am I missing something?  I think it looks beautiful, I'm just not sure for a TT.  How is the ol knock test. There is a lot of insulation for the flue and, shielded too, I bet.  Pros and Cons, ay

Great place for a horn loaded sub.. Big boom boom, in the room room..
If your not using it, if you're using the fire place, my TT really wouldn't be there, no way.. My TT are industrial, OK, they are gigantic rim drives..
Still to close to the fire to close to the corner... 10 foot ceilings would help.

I don't do TT in corners UNLES it's in the closet or the next room, the exception being a stepped corner. Kinda asking for trouble..
BUT I usually err on the side of EXTREME caution. 

Very clean, gosh...nice oh man..

Go for it. All the naysaying is based on pure speculation and worst case scenarios. Let us know how it actually works out.
I think an easy test for potential turntable placement is to place half a glass of water in the intended spot and walk around the area.  The water should remain almost perfectly still.  If it wobbles, pick someplace else. Now, the stuff about the corners and the heat is another story.  
How about just put the freakin' turntable there and listen to some music? (No disrespect intended, Chayro.)
Or, you could hit it with a hammer, pour water on it, wait for 100 mph winds to blow across your chimney, light a roaring fire and feed it with gasoline. (I must be in a bad mood.  Sorry.)
(I must be in a bad mood. Sorry.)


Yup...No gas ay. :-).
I can see the vinyl running, as I think, I think!

Ok then let me encourage you do it. Forget the reason.. All is good.
It will "Look" good there.  I wish you  the best, won't make it the best.

Again do you use the fire place? It makes a difference.. If heat and bass control isn't an issue.  You know the stuff that makes the stylus BOUNCE.. GOOD! You did something I couldn't.. If I hadn't tried something real close I wouldn't comment.. But I did..

Didn't work for me, with HUGE industrials, or my Thoren 124s/121s

They are not as picky as your TT, I assure you... The Russco's are pure boogie brother...They are made to party around the table, really...HD MM carts, just for broadcasting and station vinyl. TOUGH!!!

Ya never know though.. You may have jumped on a magic carpet, and get the best sound of your life..

@lewm - no disrespect to you either, but IMO it's alot easier to check and see if an area is vibration-prone before setting up the table and doing the wiring only to find out the arm is going off the rails every time you move.  But that's me.  We're all in a bad mood sometimes.  Especially now. 
Looks solid. You may need springs later.

The only major thing is corner placement on it's on can be problematic.
For me, a fireplace mantel is at least as stable as one of those Target wall shelves and likely to be much more so.  Plus, it is anchored into the chimney, the most structurally rigid part of most houses, certainly more rigid than a typical stud, even if the latter is weight bearing as it should be.  So, I have to ask why you think a mantelpiece might vibrate, unless the whole house is vibrating, which can occur, if you live near a major highway or if you live under an airport approach pattern, but which is usually a very transient phenomenon? Apart from that, there is nothing wrong with doing your recommended glass of water test; that would detect constant local vibration.  I just can't understand why that would happen, and if it does happen, there is likely to be no sanctified vibration-free location in the entire house.
I'll let you know as soon as I've reviewed the blueprints and the engineering reports.  
If one of the comments above was in response to my post............
because acoustical vibrations affect a tts performance more in a corner, especially if it is located behind speakers.
Don't quote me on this - but Fremer may have said placing turntables on top of a fireplace mantle adds a smoky flavor.
It is a Nice combination of Focal Points for the Room, with the TT above the Fire Place.
There is still the option to choose and Trial further aesthetically pleasing to the eye Sub Plinth Materials to help attenuate any unidentified resonances, and produce a Delivery that is satisfying to your personal preferences.
If the Focal Point is of importance, the exposed Cables might prove to be a detractor ?