dendritic agate

Quoted from James Dwight Dana's "A System of Mineralogy" in  The Collected Works of John Ruskin, Vol. 26, page 376.

Per Wikipedia: "Dendritic agates have fern like patterns in them formed due to the presence of manganese and iron oxides."

Vintage moss agate ring, originally found at Lori McLean.

Melissa Joy Manning stone ring.

American moss agate ring with gold filigree setting, c. 1910.