This is a hot one. Small, sharp and unique.
Source GraphicsWall
It looks like a polished stone surface to me. Download it for free, as always.
Source V. Hartikainen
From a drawing in 'Two Women in the Klondike', Mary Hitchcock, 1899.
Source Firkin
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-I.
Source Firkin
Remixed from a drawing in 'The March of Loyalty', Letitia MacClintock, 1884.
Source Firkin
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Light gray pattern with an almost wall tile-like appearance.
Source Markus Tinner
This seamless web background texture looks like gray stone. It's great for using as a background image on web pages, or on some of their elements. Anyway, I hope you will find use for it.
Source V. Hartikainen
It almost looks a bit blurry, but then again, so are fishes.
Source Petr Šulc
Looks a bit like concrete with subtle specks spread around the pattern.
Source Mladjan Antic
A seamless pattern formed from a modified version of rwwgub's tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
From a drawing in 'Worsborough; its historical associations and rural attractions', Joseph Wilkinson, 1879.
Source Firkin
Got some felt in my mailbox today, so I scanned it for you to use.
Source Atle Mo
ZeroCC tileable stone texture, edited from pixabay. CC0
Source Sojan Janso
Nicely crafted paper pattern, although a bit on the large side (500x593px).
Source Blaq Annabiosis
Abstract Tiled Background Extended 11
Source GDJ
You could get a bit dizzy from this one, but it might come in handy.
Source Dertig Media
Here is a new seamless wood texture for using as blog or website backgrounds.
Source V. Hartikainen
Prismatic Curved Diamond Pattern 3 No Background
Source GDJ