Dark and hard, just the way we like it. Embossed triangles makes a nice pattern.
Source Ivan Ginev
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
It almost looks a bit blurry, but then again, so are fishes.
Source Petr Šulc
Vertical lines with a bumpy, yet crisp, feel to it.
Source Raasa
Medium gray pattern with small strokes to give a weave effect.
Source Catherine
Background formed from the original with an emboss effect.
Source Firkin
A background pattern with a look of rough fabric.
Source V. Hartikainen
People seem to enjoy dark patterns, so here is one with some circles.
Source Atle Mo
Square design drawn in Paint.net and vectorized in Vector Magic.
Source Firkin
After 1 comes 2, same but different. You get the idea.
Source Hendrik Lammers
Prismatic Curved Diamond Pattern 6 No Background
Source GDJ
This background texture resembles stone. It may be used as a background on web pages or on some of their html elements (header, borders, menu bar, etc.). Just modify it for your needs.
Source V. Hartikainen
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
So tiny, just 7 by 7 pixels – but still so sexy. Ah yes.
Source Dmitriy Prodchenko
Just to prove my point, here is a slightly modified dark version.
Source Atle Mo
A seamless pattern formed from a tile made from page ornament 22. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin