19th C. Hardstone, Agate, Cameo Cravat-Stick Pin, Philosopher, Darwin?14-15K

Description

Offered at auction is a late 19th century to early 20th century Cravat or Stick pin set with a finely hand engraved, black and white, banded agate, high relief, portrait cameo of a balding philosopher or possible 19th century thinker or scientist such as Charles Darwin. I leave it up to the viewer/buyer to decide which important  and influential personage is intended.
The Cameo measures approximately 16mm by 20mm and the pin, though not marked as was common at the time of its manufacture, tests as 14K-15K solid gold.
The stick pin measures approximately 3 inches long and weighs 5.8 grams.