This is Snowflake #80 in the book of 100 Snowflakes. Instructions are on Page 92. It is pictured on Page 36 in the Showcase.

“This diaphanous design takes its name from a term for the fog formed when very cold air passes over warmer water.”

Finished diameter: 3-3/8 in. (86 mm)
Thread required: 8 yd (7.3 m)

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