This is an easy pattern. Circles are easy to crochet in general in simple dc, sc, etc.: just keep increasing groupings one more stitch farther apart for each and every new row and the circle should lay flat even if you keep going like that for forever.
Named simply 'Grey Crochet Throw', free square pattern by Elaine of ItalianDishKnits. Worked in Cascade Ultra Pima cotton for stitch definition & drape. Predominant gray is set off by touches of purple & light green.