Final answer:
The Roman naturalist known for his statement about the unparalleled value of diamonds is Pliny the Elder. His observations underscore the historical human fascination with these precious stones, symbolizing wealth and power.
Step-by-step explanation:
The Roman naturalist known for stating 'Diamond is the most valuable, not only of precious stones, but of all things in this world' is Pliny the Elder. His work in Natural History spans a wide array of subjects including geology and mineralogy, where he expounded on the virtues of diamonds and their unrivaled hardness and value. Diamonds are pure carbon and are renowned for both their beauty and their unmatched physical properties.
In historical texts, these precious stones have often been surrounded by lore and an aura of mythology. The passage cites a hypothetical scenario in which a discovery of a mountain made entirely of diamond could disrupt global economics, indicating the immense value and rarity associated with such gems.
The allure of diamonds, both in their natural and mythological contexts, has captivated humans for centuries, as evidenced by the stories and legends that encircle them. This fascination is emblematic of the pursuit of wealth and power that has defined human history, and the desire to possess that which is seen as the pinnacle of natural splendor and luxury.