The gem mine pattern!

Muzzle Mouth Mine:
Only place to find the Red Ruby Heart
All the Red Gems
Level 2 White Gems (Unicorn Horn & Yum Zum Sparkle)
Level 3 Yellow Gems (Starlight Shimmer, Lemon Drop & Carat Eclipse)
Level 3 Blue Gems (Rainbow Flower, River Ripple & Aqua Orb)

Barking Mad Mine:
Only place to find the Corona Topaz
All of the Yellow Gems
Level 2 Blue Gems (Teardrop Tower & Sea Stone)
Level 3 Red Gems (Flare Fyca, Torch Treasure & Lava Lump)
Level 3 Green Gems (Jaded Envy, Pearl Egg & Terra Tectonic)

Flea Floater Mine:
Only place to find the Earth Emerald
All of the Green Gems
Level 2 Red Gems (Ember Amber & Volcano Viscose)
Level 3 Yellow Gems (Starlight Shimmer, Lemon Drop & Carat Eclipse)
Level 3 White Gems (Zingoz Zincoz, Booger Nugget & Goober Glitter)

Howling Horse Mine:
Only place to find Ocean Sapphire
All of the Blue Gems
Level 2 Green Gems (Moss Marble & Cat's Eye Glint)
Level 3 Red Gems (Flare Fyca, Torch Treasure & Lava Lump)
Level 3 White Gems (Zingoz Zincoz, Booger Nugget & Goober Glitter)

Buried Bones Mine:
Only place to find the Webkinz Diamond
All of the White Gems
Level 2 Yellow Gems (Aurora Rox & Pyramid Plunder)
Level 3 Green Gems (Jaded Envy, Pearl Egg & Terra Tectonic)
Level 3 Blue Gems (Rainbow Flower, River Ripple & Aqua Orb)