Which stitch is this?!

[Lucyllwight]

please could someone help what stitch this is? thank you xx

 

Edited July 21, 2021 by Lucyllwight

[Granny Square]

I knit a little, and I suspect is is manufactured knit.  I don't knit enough to guess how it might be done by hand, but if you look down the center of the raised diamond shapes it looks like stockinette (knit stitches facing you).

[Granny Square]

I'm not positive that this is exactly this (knit) stitch, but it looks very similar https://www.knittingkingdom.com/lattice-pattern-knitting-stitch/

The above link's photo is showing it in thicker yarn and done in a needle size that makes a more solid fabric, your photo's fabric looks like it is done in lace weight and a bigger hook (so fabric is open and loose).