Prasiolite, green-quartz or vermarine is a green form of quartz

Quartz

Quartz is the second-most-abundant mineral in the Earth's continental crust, after feldspar. It is made up of a continuous framework of SiO4 silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall formula SiO2. There are many different varieties of quartz,...

, a silicate mineral chemically silicon dioxide

Silicon dioxide

The chemical compound silicon dioxide, also known as silica , is an oxide of silicon with the chemical formula '. It has been known for its hardness since antiquity...

. Prasiolite is one of several quartz varieties.
Since 1950, almost all natural prasiolite has come from a small Brazil

Brazil

Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...

ian mine, but it is also seen in Lower Silesia

Lower Silesia

Lower Silesia ; is the northwestern part of the historical and geographical region of Silesia; Upper Silesia is to the southeast.Throughout its history Lower Silesia has been under the control of the medieval Kingdom of Poland, the Kingdom of Bohemia and the Austrian Habsburg Monarchy from 1526...

 in Poland

Poland

Poland , officially the Republic of Poland , is a country in Central Europe bordered by Germany to the west; the Czech Republic and Slovakia to the south; Ukraine, Belarus and Lithuania to the east; and the Baltic Sea and Kaliningrad Oblast, a Russian exclave, to the north...

. Naturally occurring prasiolite is also found in the Thunder Bay

Thunder Bay

-In Canada:Thunder Bay is the name of three places in the province of Ontario, Canada along Lake Superior:*Thunder Bay District, Ontario, a district in Northwestern Ontario*Thunder Bay, a city in Thunder Bay District*Thunder Bay, Unorganized, Ontario...

 area of Canada

Canada

Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

.

Prasiolite can also be found spelled praziolite. Prasiolite can be confused with the similarly colored praseolite which results from the heat treatment of iolite, a variety of cordierite

Cordierite

Cordierite or iolite is a magnesium iron aluminium cyclosilicate. Iron is almost always present and a solid solution exists between Mg-rich cordierite and Fe-rich sekaninaite with a series formula: 2 to 2...

.

It is a rare stone in nature. Most prasiolite sold is used in jewellery

Jewellery

Jewellery or jewelry is a form of personal adornment, such as brooches, rings, necklaces, earrings, and bracelets.With some exceptions, such as medical alert bracelets or military dog tags, jewellery normally differs from other items of personal adornment in that it has no other purpose than to...

 settings. Prasiolite is heat treated amethyst

Amethyst

Amethyst is a violet variety of quartz often used in jewelry. The name comes from the Ancient Greek ἀ a- and μέθυστος methustos , a reference to the belief that the stone protected its owner from drunkenness; the ancient Greeks and Romans wore amethyst and made drinking vessels of it in the belief...

. Most amethyst will turn yellow or orange when heated producing citrine. But some amethyst will turn green when treated. Currently most all prasiolite on the market results from a combination of heat treatment and cobalt-60

Cobalt-60

Cobalt-60, , is a synthetic radioactive isotope of cobalt. Due to its half-life of 5.27 years, is not found in nature. It is produced artificially by neutron activation of . decays by beta decay to the stable isotope nickel-60...

 or E-beam irradiation

Irradiation

Irradiation is the process by which an object is exposed to radiation. The exposure can originate from various sources, including natural sources. Most frequently the term refers to ionizing radiation, and to a level of radiation that will serve a specific purpose, rather than radiation exposure to...

.

The name is derived from Greek

Greek language

Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...

 πράσον prason meaning "leek

Leek

The leek, Allium ampeloprasum var. porrum , also sometimes known as Allium porrum, is a vegetable which belongs, along with the onion and garlic, to family Amaryllidaceae, subfamily Allioideae...

" and λίθος lithos meaning "stone." This means that "prasiolite" literally means "garlic green-colored stone." The mineral

Mineral

A mineral is a naturally occurring solid chemical substance formed through biogeochemical processes, having characteristic chemical composition, highly ordered atomic structure, and specific physical properties. By comparison, a rock is an aggregate of minerals and/or mineraloids and does not...

was given its name due to its green-colored appearance.