Possible Clues:

• Gem that's very bad being put back in container
• Stone Age love dismissed by books
• One of the few gemstones that naturally occur in a single color (olive green)
• Fairy ultimately positioned over top of tree? It's a gem!
• Yellow-green gem
• Gemstone — pre-do it (anag)
• Gem fairy's presented to Dorothy
• A semi-precious variety of olivine
• Birthstone for many a Leo
• Birthstone for most Leos