From the pattern:

Any laceweight yarn which knits to the tension, preferably silk. Approx. 40g per pair of mittens.

From the designer:

I have wanted to knit myself a pair of fingerless mittens for a while. My workroom is cold and my hands suffer when I’m typing or playing the piano. Sometimes I wear nasty acrylic fingerless gloves and now they have become a sort of talisman for when I need inspiration. I hope these lacy pure silk mittens will bring everyone luck too! Each one is knitted in one piece on straight needles with two seams and a pretty figure of 8 lace pattern.