A type of hard sedimentary rock that is best remembered today for its usage to ignite gunpowder in early firearms.
Flint
This glass-like rock forms when magma cools rapidly preventing crystallization. Because it can be carved into sharp edges, it was prized by several ancient cultures for its use as an arrow-head.
Obsidian
Its very distinctive sky-blue color made it attractive since ancient times and its names is a give-away of its country of origin. Its color is also compared with the blue of robin's eggs.
Turquoise
The Amber Room might be lost to history, but a similar room made from this material has its pride of place at the Winter Palace in St. Petersburg.
Malachite
A form of beryl that is the third hardest gemstone after diamond and corundum. Varieties include the valuable alexandrite as well as the golden-yellow cymophane popularly called as cat's eye.
Chrysoberyl
The blue-colored larimar, also called "Stefilia's Stone" can be found only in this second-largest Caribbean country.
Dominican Republic
Till copious amounts were discovered in Brazil in the nineteenth century, this gemstone was very valuable. The Braganza diamond in the Portuguese crown is actually this. Also the title of a 1969 Hitchcock thriller.
Topaz
A form of gypsum best known for its use in making white indoor carvings. It is also used to make plaster of Paris.
Alabaster
This type of igneous rock is the most common rock on earth's surface (nearly 70%) and is usually the first lava that issues from a volcano. Cultural artifacts made from it include the Moai of the Easter Islands and the Rosetta Stone.
Basalt
The hardest gemstone after diamond is this substance of which ruby and sapphire are two varieties.
Corundum
This sedimentary rock is formed from calcium carbonate that is the remains of marine organisms, and hence fossils are abundant in it. Since it dissolves and erodes via the action of water, most cave systems are formed from this. The best known natural formations include the White Cliffs of Dover and the Rock of Gibraltar.
Limestone
This porous floating stone (which eventually sinks) is seen after volcanic eruptions.
Pumice
Strongly associated with China where it is called as a royal gem. Also associated with Maoris. Because of its beneficial effect on the kidneys, the stone was also known as 'lapis nephriticus.'
Jade
Pyrope is a popular variety of this deep-red gemstone whose name has the same roots as that of a fruit with many seeds. Noah is said to have used the light from it to help him steer his ark through the dark night.
Garnet
Semi-precious stone that exhibits a greater range of color than any other gem. According to an old Egyptian legend, on its long 'tour' up from the center of the Earth, it passed over a rainbow and hence its vibrant colors.
Tourmaline
Valuable form of corundum which gets its color from chromium and whose deep color is sometimes compared to pigeon blood.
Ruby
National gemstone of Australia as the country produces a large percentage of it. Though known for its striking color effect, the black variety of it is considered the most precious.
Opal
An entire quiz can be written on this - here's one clue - bort and carbonado are less preferred varieties of this substance and they are used in drill bits and saws.
Diamond
By definition, it is fossilized tree resin. Brought into popular consciousness by Michael Crichton who based his story of Jurassic Park by having dino DNA embedded in it.
Amber
The popular violet form of quartz is this substance, thought to be of protection against intoxication!
Amethyst
Name given to the mineral olivine when it is of gem quality. As its name indicates, it occurs only in one color - olive green. Birthstone of August which was called 'Emerald of the Evening' by the Romans.
Peridot
Collective name given to a wide variety of minerals whose forms include onyx and sardonyx. Used to make playing marbles and a famous cultural artifact made from it is the Rubens Vase of the Byzantine Empire.
Agate
A type of sandstone that was popularly used as a building material and lent its name to rowhouses in residential city blocks.
Brownstone
Valuable variety of beryl strongly associated with Colombia. Cleopatra is said to have had a thing for them.
Emerald
The correct pronunciation of this common metamorphic rock is just like the English word 'nice'.
Gneiss
While the red variety of corundum is called a ruby, all other colors of it get this name.
Sapphire
This is formed when limestone metamorphs under high heat. Some of the greatest creations of mankind, including a certain Indian building and several works of Renaissance sculpture, are in this medium.
Marble (Taj Mahal, David)
As its name indicates, this type of sedimentary rock is composed of several rounded fragments. Most people come across this word as a term for a collection of companies.
Conglomerate
Very distinctive sedimentary rock which shows layers. Landscape of the state of Utah is littered with examples and the most prominent of which is the Rainbow Bridge National Monument. Monument Valley is another example.
Sandstone
Mudstone metamorphoses into this type of smooth rock which has its uses in classrooms, billiards tabletops as well as roofing material.
Slate
Feldspar is the most common rock forming mineral and is five times as abundant as quartz. One of the best known varieties is this variety that is also the title of a Wilkie Collins work considered the first detective novel in English.
Moonstone
Sar-i Sang in Afghanistan has been the source of this stone since ancient times. The pigment of ultramarine, a favorite of several Renaissance artists, is produced by grinding it.
Lapis lazuli
Devil's Marbles in Australia, Half Dome of Yosemite as well as Mount Rushmore are occurrences of this igneous rock, a favorite go-to for home improvement.
Granite