"We found 'em! We found 'em!" they called as they came within sight of the tents. "We got the blue rocks!"
"Well, they're pretty, certainly," said Grandpa Martin, as he picked up one from the wagon, "but they're no better than any other rocks around here, as far as I can see."
"They've got gold in 'em, Hal says," Ted stated.
"Gold? Oh, no, Curlytop!" laughed his grandfather. "I've told you there is no gold on this island."
"There's something in the blue rocks," declared Hal. "Feel how heavy they are—lots heavier than any other stones around here."
"Yes, they are," agreed Grandpa Martin, as he weighed one of the
stones in his hand. "There might be some iron in them, but not gold.
Look out!" he suddenly called as the stone slipped from his hand.
"Look out for your toes!"
Laughing, the Curlytops and Hal jumped back. The blue stone which Grandpa Martin dropped, struck on the edge of the shovel which was out in front of the tent. As the rock hit the steel tool with a clang, something queer happened.
At once the rock began to burn with a curious blue flame, and a yellowish smoke curled up.
"Oh, the rock's on fire!" cried Janet. "The rock's on fire!"
"Yes, and look!" added Ted. "It's burning blue, just like the light we saw on the island one night."