On the shapes of stones, etc.

...[named]. According to Pliny, the Acopis gem is "starred with golden drops" original: aureis guttis stellata. The Acopis was a translucent stone thought to relieve weariness when used as an ointment.; and another kind of Prase original: Prasij; a leek-green variety of quartz or chalcedony is distinguished by blood-red points. A certain Ophites Serpentine, named for its resemblance to the skin of a serpent is ash-colored and variegated with points, which Dioscorides calls speckled original Greek: καταστιγμένος (katastigmenos), meaning marked or branded with spots. Epiphanius Saint Epiphanius of Salamis, a 4th-century bishop who wrote on the twelve gems of the High Priest's breastplate. describes a species of Sapphire as golden-spotted original Greek: χρυσόστιγῆ (chrysostige). Note that the "sapphire" of the ancients was often what we now call Lapis Lazuli, which contains "golden" specks of pyrite., that is, sprinkled with golden points. Larger than points are "bubbles" original: bullæ and "warts" original: verrucæ. Blue bubbles sometimes surround the Ostracites original: Ostracitin; a stone named for its resemblance to a shell or tile mentioned by Pliny, while wart-like bumps make the Myrmecias named from the Greek myrmex (ant), describing small, ant-like or wart-like protrusions feel rough.

In the general category of stones—such as common rocks, cliffs, crags, and marbles—there is no fixed or certain shape. For although every individual among solid bodies possesses some figure or form, they lack a specific and universal shape characteristic of their whole class.

On the other hand, among gemstones and smaller stones which possess some special power original: vis; referring to the traditional belief in the medicinal or magical virtues of gems or inspire wonder, most have a definite shape or form. This is because their nature is more perfect and more clearly defined, being further removed from the raw state of crude matter. Many stones are named after the resemblance of their form—and more rightly so, those which...