The image depicts a seamless pattern of a snow crystal.I referred to a book called ”sekka-zusetsu” or "雪華図説" which means an illustrated explanation about snow crystals.This book was published in 1832 (天保3年) or Edo period.For more about "雪華図説",see here:dl.ndl.go.jp/info:ndljp/pid/2536975
Source Yamachem
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Colour version of the original pattern.
Source Firkin
Colorful Floral Background 3 No Black
Source GDJ
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Background formed from the original with an emboss effect
Source GDJ
This one resembles a black concrete wall when is tiled. It should look great, at least with dark website themes.
Source V. Hartikainen
A seamless pattern the starting point for which was a 'colour modulo' texture in Paint.net.
Source Firkin
Not the Rebel alliance, but a dark textured pattern.
Source Hendrik Lammers
This one takes you back to math class. Classic mathematic board underlay.
Source Josh Green
A beautiful dark wood pattern, superbly tiled.
Source Omar Alvarado
A bit strange this one, but nice at the same time.
Source Diogo Silva
Sounds French. Some 3D square diagonals, that’s all you need to know.
Source Graphiste
Prismatic Groovy Concentric Background No Black
Source GDJ
Prismatic Geometric Pattern Background 2
Source GDJ
Remixed from a drawing that was uploaded to Pixabay by DavidZydd
Source Firkin