Where the gray comes from
Travertine forms where mineral-rich water emerges at a spring and deposits calcium carbonate as it cools and loses carbon dioxide. Whatever else is dissolved in that water comes out with it, and iron compounds are what produce the familiar warm tones.
Where the water carried little iron, the stone stays close to the color of the carbonate itself, which runs white through silver to a mid gray. The beds that produce it are less common than the warm ones, which is why gray is a small part of any travertine range.
Silver travertine
The series here is silver, which is the trade name for the gray travertines of Turkey, and it is the stone most people mean by gray travertine.
It runs from a pale silver-white to a definite mid gray, often with faint banding visible, and the tone varies bed to bed in the same quarry. Shade variation on these pieces reads medium, which is what a layered sedimentary stone produces.
The finishes on a gray travertine
Most of what is here is honed, with honed and filled, brushed and tumbled faces alongside it.
Each of those is a different answer to the same question, which is what to do about the voids. Filling closes them and honing flattens the surface; brushing leaves them open and softens the face; tumbling rounds the edges of the piece as well and gives an aged, worn surface. Travertine tile sets out what filling is and when it is done.
Why gray travertine suits a cool palette
This is the practical reason the stone exists as a category. A cream or walnut travertine brings warmth into a room whether or not the room wanted it, and in a scheme built on gray, white and cool metals that warmth fights everything else.
A gray travertine gives the texture, the layering and the visible history of the stone without the warm cast, which puts travertine into rooms that would otherwise have gone to a limestone or a porcelain.
Gray travertine against gray limestone
The two are close enough to confuse in a photograph and they were made differently. A limestone settled out of water as sediment over a very long period; a travertine was deposited quickly at a spring, which is what gives it layers and open voids.
At close range that difference is the whole character. A gray limestone is even and quiet with almost nothing happening in its face; a gray travertine has banding, texture and the record of how it formed. Limestone tile is the calmer of the two.
Formats and the half inch
The sizes run 4x4, 12x12, 12x24 and 18x18, with several pieces at a half inch thick rather than the more usual 3/8.
The extra depth is worth noting where this tile meets another floor, since half an inch stands higher than a 3/8 inch tile in the next room and the difference has to be taken up underneath or covered at the threshold.
Where gray travertine goes
A floor, a bathroom, a shower wall, a hall and a fireplace surround, and outdoors on a terrace in the thicker pieces. It handles the same places a cream travertine does and sits in schemes the cream one cannot.
Travertine tile is the full range, travertine pavers the outdoor version, and travertine look tile the printed alternative.
