This shows irony because the author made Mr. Jones seem like a really good guy. But then he shows up with a gun threatening to kill the kids for the diamonds.
There was internal conflict within Darius because when he was young, his parents died in a car crash. This event was hard for him and to try and adapt to this tragic event.
Darius shows determination throughout this story. he shows determination when his grandpa told him that looking for the diamonds could lead to death. even though his grandpa told him that, he was still determined to find them.