This is Snowflake #85 in the book of 100 Snowflakes. Instructions are on Page 96. It is pictured on page 37 in Showcase.

“This large, fluffy flake could have floated to the ground at the beginning of a November snowstorm.”

Finished diameter: 3.5 in. (89 mm)
Thread required: 11 yd (10.1 m)

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