Crochet Block: Spiral

The edging design worked into the open mesh spiral could be adapted to any filet design.

Foundation chain: Using yarn A, ch 35
Row 1: (as chart) yo, insert the hook into the 4th ch from the hook, work 1dc, dc into the next ch, this completes the first mesh. Cont to the end of the row using the chart as reference and counting each ch as either a sp or a st. Read the chart from right to left on odd numbered rows and left to right on even numbered rows. Turn. 
Row 2: Ch 2 (counts as 1dc) cont to the end of the row, work the last dc into the 2nd ch of the beg-ch.Turn. 
Cont to work as the chart, ch 2 (counts as 1dc) at the beginning of each row, and work the last dc into the top of beg-ch before turning. 
Fasten off yarn.
Make slip knot in yarn B and, starting from the center, surface crochet the open mesh squares *insert the hook into the next block, ch 2, rep from * to the end of the spiral. Turn.
Next row: Ch 3 (counts as 1dc), 1dc into the next ch, *1hdc into the next ch, 1sc into the next ch, sl st into each of the next 2 ch, 1sc into the next ch, 1hdc into the next ch, 1dc into each of the next 2 ch, rep from * to the end. Turn.
Next row: Ch 2 (counts as 1dc), sl st into the sl sts of the previous row and work 2dc into each of the other sts.
Fasten off yarn.

Variation
Work the as above but omit the surface crochet and the subsequent rows.

om open mesh-ch 1, sk 1 sp or dc, dc into the next dc st
sm solid mesh-dc into the next sp or st, dc into the next dc st

ABBREVIATIONS / REFERENCES Click for explanation and illustration

beg = begin(s)(ning) hdc = half double crochet
ch(s) = chain(s) sc = single crochet
cont = continu(e)(s)(ing) sk = skip
dc = double crochet sp(s) = space(s)
foll = follow(s)(ing) st(s) = stitch(es)

Pattern by permission from Crochet Blocks in a Box by Luise Roberts, St. Martin's Griffin, 2007