STONE DICTIONARY
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QUARTZ
HARDNESS 7
Highly transparent specimens are called quartz crystal. It is a mineral composed of crystallized silicon dioxide, often forming beautiful hexagonal prisms.
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GRANITE
HARDNESS 6.5
A major rock type found on Earth's continents, and it can be observed worldwide. However, its formation requires the influence of water, which is why it is rarely found on other planets in the universe.
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BASALT
HARDNESS 6.5
A rock formed when magma solidifies on the Earth's surface. It's said that about 70% of the Earth's ocean floor is made up of basalt. Hawaii, Java Island, and Iceland are also composed of basalt.
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AGATE
HARDNESS 6.5
A mineral formed by the overlapping of layers of quartz or opal. The opaque variety is called chalcedony, while those with striped patterns or semi-transparency are called agate. It is one of the Seven Treasures in Buddhism.
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JADE
HARDNESS 6
An aggregate of fine-grained jadeite and nephrite forms this mineral. Jadeite is harder, while nephrite is softer, and both appear translucent when illuminated. It has been crafted and utilized as jewelry and everyday items since ancient times.
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PERIDOT
HARDNESS 7
A mineral that dominates much of the uppermost part of the Earth's mantle. During volcanic eruptions, magma brings it to the surface from underground. It emits a melting-like olive-colored luster and is known as peridot, the birthstone for August.
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SERPENTINE
HARDNESS 3
A rock formed deep underground when water mixes with olivine. Named for its surface pattern resembling snakeskin.
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RODIN ROCK
HARDNESS 3
Formed when water alters peridotite into serpentinite, calcium precipitates to create this green mineral. Often mistaken for jade, it is also known as “fox stone.”
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RHYOLITE
HARDNESS 6
A rock formed by the rapid cooling and solidification of magma at or near the Earth's surface. Its name derives from the flowing patterns of magma that appear during this process.
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CHERT
HARDNESS 7
A rock formed from the accumulation of the remains of organisms such as radiolaria that existed during the Cambrian period. It is exceptionally hard due to compression at the bottom of the deep sea.
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QUARTZ DIORITE
HARDNESS 6
A rock appears white with striking quartz crystals and small surface holes. Weathering leads to oxidized iron deposits, resulting in distinctive reddish-brown patterns. Commonly found in mountainous regions, it forms through slow-cooling processes.
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SERGEANTITE
HARDNESS 6
A metamorphic rock consisting of the mineral serpentine. It lacks transparency but is overall sparkly due to the presence of quartz. Resembles jade but is lighter and softer in comparison.
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ANDESITE
HARDNESS 4.5
A rock formed by the rapid solidification of magma at the Earth's surface. It typically consists of a thin grayish layer with a mixture of slowly crystallized portions and quickly cooled segments. The name "andesite" originates from the abundant deposits found in the Andes Mountains of South America.
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DIORITE
HARDNESS 6
A rock forms as magma slowly solidifies deep underground. It characterized by its speckled appearance, typically composed of light and dark minerals charis acterized by its speckled appearance, typically composed of light and dark minerals
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MUDSTONE
HARDNESS 2.5
A rock formed from the consolidation of mud on the seabed or lake floor 50 to 300 million years ago. Fossils are sometimes found within it. It has a smooth texture and is prone to scratching.
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OBSIDIAN
HARDNESS 5
Obsidian is a naturally occurring black glass formed when magma erupts onto the Earth's surface and rapidly cools. It has been widely used since the Stone Age for various purposes including hunting and cooking.
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LIMESTONE
HARDNESS 3
A rock formed from the accumulation of remains such as coral, foraminifera, and shells, which inhabited tropical seas from the Ordovician period to the Middle Ages, around the Cretaceous period.
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SANDSTONE
HARDNESS 3
A rock formed from the accumulation and consolidation of sand. It is said to take at least 10 to 20 million years for sand to become sandstone, and it often exhibits layered formations due to wave action.
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CALCITE
HARDNESS 3
A soft mineral composed of calcium carbonate (CaCO3), and it effervesces when exposed to acids like vinegar or lemon juice.
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MAGNETITE
HARDNESS 6
A dark-colored rock containing iron ore, used for extracting iron by heating and producing steel.