Vintage Brooch- Cris-cross Tools with Mystery Blue Stone

This collection came to me as part of an estate. Vintage Brooch-and I have no idea what this is supposed to represent.  There are two tools, crossed.  Gardening maybe?  And the stone- your guess is as goods as mine.  The woman who made this was fascinated by gemstones, and although I am not a gemologist, I usually know which is what.  This one - - ? Approx 2.5" high by 1.5" wide.