Latin and Greek names of some semi-precious & precious stones agate:

Agate was discovered with the Stone Age man in France 20,000-16,000 BC. The Egyptians used it prior to 3000 BC. Agate was highly valued by ancient civilizations. Said by the ancients to render the wearer invisible. Agate derives its name from the Greek "Agateес" – meaning happy.  According to another theory the word Agate comes from the Greek name of a stone found in the Achates River in Sicily, now known as the Drillo River, which still remains a major source of this stone.

Amethyst:

The story of the origin of amethyst comes from Greek legends: The god of wine, Bacchus, was insulted one day by a mere mortal. He swore the next mortal that crossed his path, would be attacked by his fierce tigers. Along came a beautiful maiden named Amethyst. Goddess Diana turned Amethyst in a beautiful statue of quartz to save her from the tigers claws. Remorseful Bacchus wept tears of wine over the stone maiden, creating a lively purple stone. Amethyst derives its name from Middle English amatist, from Old French, from Latin amethystus, from Greek amethustos, not drunk or intoxicating.

Garnet:

Garnets were so called by the ancient Greeks since color reminded them of the pomegranate seed or granatum. One of the world's most ancient gems, garnet has been treasured for thousands of years. The hardness of garnets and their sharp fracture make them suitable as abrasives for wood, leather, glass, metals, and plastics. Garnet varieties have become known by misleading names, frequently consisting of a locality with the name of another mineral variety, such as Uralian emerald or Cape ruby.

Hematite:

Hematite or Haematite (as it also sometimes known as,) derives its name from the Greek word haem (blood ) in allusion to its red color. Ancient Egyptians used hematites as ornamental objects placed inside their tombs. Red ochre was used by prehistoric artists in their cave paintings. Nowadays hematite may also be used as a polishing powder and as a paint pigment.

Iolite:

The name Iolite is derived from the Greek "los", meaning violet. It was also known as the Vikings' compass, due to its ability to determine the direction of the sun on overcast days. When the legendary Viking mariners sailed the wide ocean, they used thin pieces of iolite as the world's first polarizing filter. Looking through an iolite lens, they could determine the exact position of the sun, and navigate safely. The natural mineral has little commercial use. When clear, iolite is cut as a gem.

Jasper:

The name jasper is derived from the Greek word iaspis. In ancient writings the term jasper was chiefly applied to translucent and brightly colored stones, particularly chalcedony, but also was applied to the opaque jasper. Jasper was known as the great "rain-bringer" in the fourth century. For thousands of years, black jasper was used to test gold-silver alloys for their gold content. Rubbing the alloys on the stone, called a touchstone, produces a streak the color of which determines the gold content within one part in one hundred.