Pattern in English and French.
En Français aussi, alias Rose losange

Diamond Rose
Diamond Rose is a perfect gift pattern that is a really quick knit if you are familiar with Icelandic intarsia, an old tradition that was almost lost and is seen mostly in knitted shoe inserts. It is, however, a very good introduction to Icelandic intarsia and to some of the more challenging designs in my book. You will find a useful tutorial here.
Diamond Rose can be made both as a brooch or a fancy button. You can use any scraps of yarn, even the shortest ones., and there is no need to darn ends.