This is Snowflake #70 in the book of 100 Snowflakes. Instructions are on Page 85. It is pictured on page 34 in the showcase.

“Lifted by a high wind, crystals like this one can obscure visibility with a curtain of snow.”

Finished diameter: 3 1/2 in (89 mm)
Thread required: 12 yd (11 m)

All pattern samples in this book are made with size 10 thread and a size 5 (1.9 mm) crochet hook.