This is a reversible pattern stitch, although the wrong side is not identical.
Cast on a multiple of 17 stitches.
Row 1 – wrong side: Purl 1, knit 3, purl 9, knit 3 * purl 2, knit 3, purl 9, knit 3; repeat from * to last stitch, purl 1.
Row 2 - right side: Knit 2, purl 3, knit 7, purl 3, * knit 4, purl 3, knit 7, purl 3; repeat from * to last 2 stitches, knit 2.
Row 3: Purl 3, knit 3, purl 5, knit 3, * purl 6, knit 3, purl 5, knit 3, repeat from * to last 3 stitches, purl 3.
Row 4: Knit 4, purl 3, knit 3, purl 3, * knit 8, purl 3, knit 3, purl 3; repeat from * to last 4 stitches, knit 4.
Row 5: Purl 5, knit 3, purl 1, knit 3, * purl 10, knit 3, purl 1, knit 3; repeat from * to last 5 stitches, purl 5.
Row 6: Knit 6, purl 5, * knit 12, purl 5; repeat from * to last 6 stitches, knit 6.
Row 7: Purl 7, knit 3, * purl 14, knit 3; repeat from * to last 7 stitches, purl 7.
Row 8: Knit 6, purl 5, * knit 12, purl 5; repeat from * to last 6 stitches, knit 6.
Row 9: Purl 5, knit 3, purl 1, knit 3, * purl 10, knit 3, purl 1, knit 3; repeat from * to last 5 stitches, purl 5.
Row 10: Knit 4, purl 3, knit 3, purl 3, * knit 8, purl 3, knit 3, purl 3; repeat from * to last 4 stitches, knit 4.
Row 11: Purl 3, knit 3, purl 5, knit 3, * purl 6, knit 3, purl 5, knit 3, repeat from * to last 3 stitches, purl 3.
Row 12: Knit 2, purl 3, knit 7, purl 3, * knit 4, purl 3, knit 7, purl 3; repeat from * to last 2 stitches, knit 2.
Repeat Rows 1 - 12.

Inverness Diamond stitch in the round