How the surface is made
A mirror is a sheet of glass with a thin metallic layer on the back and a protective coat over that. To antique it, the backing is treated so the metal breaks up into clouds, speckles and thin patches, and the coat is applied over the result.
Light still reaches the remaining silver and comes back through the glass, so the surface is bright. An image cannot survive the journey, because the reflecting layer is no longer continuous. What you see is a soft silvered haze with darker mottling through it.
Why a broken mirror is more useful than a whole one
A full mirror on a kitchen or bathroom wall doubles the room and shows everything in it, including the person standing at the counter and everything on it.
An antiqued one keeps the brightness and drops the image. In a narrow galley or a small bathroom that is the practical difference between a wall that opens the room up and a wall nobody can relax in front of.
No two pieces are alike
The antiquing is a chemical process acting on a metal layer, and it produces a different pattern of clouding on every sheet.
So a wall of antique mirror varies piece to piece in the way a natural stone does, which is unusual for a manufactured material. The variation is the product rather than a tolerance, and a sample shows the character rather than the piece that will arrive.
Why the color field reads gray
These pieces are listed as gray rather than silver or clear, and that is an accurate description of what an antiqued mirror actually returns.
A clean mirror has no color of its own, since it hands back whatever is in front of it. Once the silvering is broken up, the light that comes back has passed through the glass twice and bounced off a patchy metal layer, and it loses a little on each pass. The result reads as a warm gray with a silver lift in it, which is why an antique mirror never looks as bright as the mirror it started as.
The formats here
3x6 and 12x24, in a gray glossy finish, at 3/8 inch and a thinner 13/64 inch.
Those two sizes do different jobs. A 3x6 antique mirror laid in a running bond gives a wall of small bright rectangles with visible joints, which reads as a deliberate surface. A 12x24 gives larger unbroken areas and reads closer to a panel of aged glass.
Where the joints go
Glass and mirror at this thickness sit thinner than most tile, which matters where a mirror panel meets a stone or ceramic field.
It also matters at the edges. A mirror tile has a cut glass edge, so a run of it usually finishes against a metal profile or into a reveal rather than stopping in the open. That is a decision to settle before the quantity is fixed.
Where antique mirror goes
A backsplash, a panel behind open shelving, the back of a cabinet, a bar wall, a dining room wall and the recess of an alcove. It belongs to rooms that need light more than they need another surface to look at.
Glass tile holds the material in its transparent and colored forms, and backsplash tile the wall in every material.
