This is Design 52 from Tatting - 60 Original Lace Treasures by Christel Weidman. Although I've only done one motif from this book, it's one of my favorites as there are a ton of edgings that can be combined into rounds for custom one-of-a-kind doilies. The color is Lizabeth Denim Whisper #120 and is 5.25" across.
And I'm very excited to announce that with Motif 11, the Diamond Doily, I have completed all of my UFO tatting projects. I still haven't been able to find the pattern for this coaster so I have decided it is done as is. As of this writing I'm done, anyway. No telling how many projects I will start and abandon for what ever reason in the next hours/days/weeks.