Rusher's Gold

A time traveling cave. A vicious band of miners…and pure gold.
When West Virginia teenagers Emma and Brody promised their neighbor, a famous geologist, to help rebuild his decimated rock and mineral collection for a museum display, they didn't know they would be in for the magical ride of a lifetime.
After a successful trip to 1775 England where they collected the rare Blue John Fluorite, the teens are quick to jump at the chance to travel to the California Gold Rush in 1851. When they arrive at the Gold Rush and meet an old acquaintance, they think the mission will be easy until they realize their friend may not be able to help them at all.
When their actions in the past erase their future, can Emma and Brody right the wrong? With a hostile group of miners hot on their trail, Brody and Emma must collect the gold, save their friends, and salvage the future before it is too late.
Rusher's Gold is the second book in the middle grade adventure/sci-fi series Crystal Cave Adventures. If you like adventure and time travel mixed with your geology, then you'll love Tracy Barnhart's exciting series.