What Stone Is It?

[Ivan]

Hi guys,

The inside of the stone caught my attention, so I went ahead and decided to turn to your help. You know much more than I do in this field.
Can you help me identify the stone from the images? Is it something unique, or is it just a regular stone?

[Geologyhound]

Not sure of the exact name of your stone, as there are a variety of cryptocrystalline yellowish rocks.  Some additional information like hardness and streak color would help.  Will this rock scratch a penny, glass, or other Moh’s hardness index materials? If you scraped it across some unglazed porcelain, would it leave any color behind, and if so, what color?  There are several processes which can generate a “shell” on a rock.  One of the most common shells is called a weathering rind.  This is a result of mechanical or chemical alteration of the exposed surface.  Weathering rinds are a common occurrence.

[jasong]

Agree with Geologyhound, looks like chert with a weathering rind most likely.

Sorta resembles a common opal nodule, these also tend to have outer rinds, but it's softer and will scratch with a knife. This would be the less likely scenario. 

[Ivan]

Thank you, Geologyhound!

Thank you, jasong!