Opals

I've known that opals tended to be found in Hungry, South Australia and Russia during the 19th Century but I came across this tidbit and thought of it's uniqueness.

OPALS.
Milky opals that gleam and shine, lake sullen fires in a pallid mist. A large collection of these both cut and uncut. Most of them were collected by the geologist of the San Domingo Expedition, Prof. Gabb. They arefull of fire and are the true precious opal. Price from 25 cents to $2.00. Also the variety of opal called geyserite, or Pealite, from the Yellowstone National Park. Price 25 cents to $2.00. At the Centennial Exposition, even the diamonds did not attract as much attention as the opals.
Source: The Naturalists' Leisure hour and monthly bulletin ©1840