Dilly Diamond coaster is a large size, textured square coaster that is designed to be used for those ginormous coffee mugs. The texture in this pattern is obtained by placing stitches in the three loops of the half double crochet stitches. About 3-4 coasters can be made with 170m of worsted weight cotton yarn, which is about 100g.

This pattern is available for free on my blog https://yarnnme.com/dilly-diamond-coaster/