A friend got them from her grandson in Colorado. He said that when he busted open one of the "nodes," there was just dust inside. Thanks for any assistance. They're very heavy.
Can anyone tell me how to upload the images?
The images would definitely help. You can use the picture upload icon next to the quotes icon above the editor.
If they are very heavy they could be barite concretions. Whats the surrounding rock type? And where in Colorado do these originate from?