If you like it a bit trippy, this wave pattern might be for you.
Source Ian Soper
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Same as gray sand but lighter. A sandy pattern with small light dots, and some angled strokes.
Source Atle Mo
Prismatic Curved Diamond Pattern 2 No Background
Source GDJ
A very dark spotted twinkle pattern for your twinkle needs.
Source Badhon Ebrahim
This is the remix of "polka dot seamless pattern".The image depicts polka dot seamless pattern.
Source Yamachem
Like the name suggests, this background image consists of a pattern of dark bricks. It may be an option for you, if you are looking for something that looks like a brick wall for use as a background on web pages. It's not a masterpiece, but looks pretty nice when is tiled.
Source V. Hartikainen
It looks like a polished stone surface to me. Download it for free, as always.
Source V. Hartikainen
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A repeating background for websites with a texture of black groove stripes.
Source V. Hartikainen
Pattern Background, Texture, Photoshop Structure style CC0 texture.
Source Darkmoon1968
Light gray grunge wall with a nice texture overlay.
Source Adam Anlauf
Black And White Floral Pattern Background Inverse
Source GDJ