I found this geode-like rock (spheroidal shaped with empty spheroidal cavity inside) near Dickson Tennessee, USA. Comments suggest that this is in fact geode, but it is empty and featureless inside.
The white on the outer part is soft and can be flaked off.
- Can this still be a geode? Assuming it is, why might this one be empty inside instead of being full of crystals?
- Would this be indicative that most geodes in this area are likely to be empty as well, or would there be no correlation between one and another?
Click any image for full-size view, scale is in inches: