Hemimorphite, is a sorosilicate

Silicate minerals

The silicate minerals make up the largest and most important class of rock-forming minerals, constituting approximately 90 percent of the crust of the Earth. They are classified based on the structure of their silicate group...

 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...

 which has been mined from days of old from the upper parts of zinc

Zinc

Zinc , or spelter , is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2...

 and lead

Lead

Lead is a main-group element in the carbon group with the symbol Pb and atomic number 82. Lead is a soft, malleable poor metal. It is also counted as one of the heavy metals. Metallic lead has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed...

 ore

Ore

An ore is a type of rock that contains minerals with important elements including metals. The ores are extracted through mining; these are then refined to extract the valuable element....

s, chiefly associated with smithsonite

Smithsonite

Smithsonite, or zinc spar, is zinc carbonate , a mineral ore of zinc. Historically, smithsonite was identified with hemimorphite before it was realised that they were two distinct minerals. The two minerals are very similar in appearance and the term calamine has been used for both, leading to some...

. It was often assumed to be the same mineral and both were classed under the same name of calamine

Calamine (mineral)

Calamine is a historic name for an ore of zinc. The name calamine was derived from the Belgian town of Kelmis, whose French name is "La Calamine", which is home to a zinc mine...

. In the second half of the 18th century it was discovered that there were two different minerals under the heading of calamine - a zinc carbonate

Carbonate

In chemistry, a carbonate is a salt of carbonic acid, characterized by the presence of the carbonate ion, . The name may also mean an ester of carbonic acid, an organic compound containing the carbonate group C2....

 and a zinc silicate, which often closely resembled each other.

The silicate was the more rare of the two, and was named hemimorphite because of the hemimorph development of its crystal

Crystal

A crystal or crystalline solid is a solid material whose constituent atoms, molecules, or ions are arranged in an orderly repeating pattern extending in all three spatial dimensions. The scientific study of crystals and crystal formation is known as crystallography...

s. This unusual form, which is typical of only a few minerals, means that the crystals are terminated by dissimilar faces. Hemimorphite most commonly forms crystalline crusts and layers, also massive, granular, rounded and reniform aggregates, concentrically striated, or finely needle-shaped, fibrous or stalactitic, and rarely fan-shaped clusters of crystals.

Some specimens show strong green fluorescence

Fluorescence

Fluorescence is the emission of light by a substance that has absorbed light or other electromagnetic radiation of a different wavelength. It is a form of luminescence. In most cases, emitted light has a longer wavelength, and therefore lower energy, than the absorbed radiation...

 in shortwave ultraviolet

Ultraviolet

Ultraviolet light is electromagnetic radiation with a wavelength shorter than that of visible light, but longer than X-rays, in the range 10 nm to 400 nm, and energies from 3 eV to 124 eV...

 light (253.7 nm) and weak light pink fluorescence in longwave UV.

Occurrence

Hemimorphite most frequently occurs as the product of the oxidation of the upper parts of sphalerite

Sphalerite

Sphalerite is a mineral that is the chief ore of zinc. It consists largely of zinc sulfide in crystalline form but almost always contains variable iron. When iron content is high it is an opaque black variety, marmatite. It is usually found in association with galena, pyrite, and other sulfides...

 bearing ore bodies, accompanied by other secondary minerals which form the so-called iron cap or gossan

Gossan

Gossan is intensely oxidized, weathered or decomposed rock, usually the upper and exposed part of an ore deposit or mineral vein. In the classic gossan or iron cap all that remains is iron oxides and quartz often in the form of boxworks, quartz lined cavities retaining the shape of the dissolved...

. Hemimorphite is an important ore

Ore

An ore is a type of rock that contains minerals with important elements including metals. The ores are extracted through mining; these are then refined to extract the valuable element....

 of zinc and contains up to 54.2% of the metal.
The regions on the Belgian

Belgium

Belgium , officially the Kingdom of Belgium, is a federal state in Western Europe. It is a founding member of the European Union and hosts the EU's headquarters, and those of several other major international organisations such as NATO.Belgium is also a member of, or affiliated to, many...

-German

Germany

Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

 border are well known for their deposits of hemimorphite of metasomatic origin, especially Vieille Montagne

Vieille Montagne

Vieille Montagne is the name of a former zinc mine in Kelmis , a town in Belgium between Liège and Aachen. The mine's name is French for "the old mountain", and this is also reflected in its German name, Altenberg...

 in Belgium

Belgium

Belgium , officially the Kingdom of Belgium, is a federal state in Western Europe. It is a founding member of the European Union and hosts the EU's headquarters, and those of several other major international organisations such as NATO.Belgium is also a member of, or affiliated to, many...

 and Aachen

Aachen

Aachen has historically been a spa town in North Rhine-Westphalia, Germany. Aachen was a favoured residence of Charlemagne, and the place of coronation of the Kings of Germany. Geographically, Aachen is the westernmost town of Germany, located along its borders with Belgium and the Netherlands, ...

 in Germany. Other deposits are near Tarnovice in upper Silesia

Silesia

Silesia is a historical region of Central Europe located mostly in Poland, with smaller parts also in the Czech Republic, and Germany.Silesia is rich in mineral and natural resources, and includes several important industrial areas. Silesia's largest city and historical capital is Wrocław...

, 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...

; near Phoenixville

Phoenixville, Pennsylvania

Phoenixville is a borough in Chester County, Pennsylvania, United States, northwest of Philadelphia, at the junction of French Creek with the Schuylkill River. The population is 16,440 as of the 2010 Census.- History :...

, Pennsylvania

Pennsylvania

The Commonwealth of Pennsylvania is a U.S. state that is located in the Northeastern and Mid-Atlantic regions of the United States. The state borders Delaware and Maryland to the south, West Virginia to the southwest, Ohio to the west, New York and Ontario, Canada, to the north, and New Jersey to...

; the Missouri

Missouri

Missouri is a US state located in the Midwestern United States, bordered by Iowa, Illinois, Kentucky, Tennessee, Arkansas, Oklahoma, Kansas and Nebraska. With a 2010 population of 5,988,927, Missouri is the 18th most populous state in the nation and the fifth most populous in the Midwest. It...

 lead-zinc district; Elkhorn

Elkhorn, Montana

Elkhorn is a small ghost town in Jefferson County, Montana, United States, in the Elkhorn Mountains of the southwestern part of the state.-History:...

, Montana

Montana

Montana is a state in the Western United States. The western third of Montana contains numerous mountain ranges. Smaller, "island ranges" are found in the central third of the state, for a total of 77 named ranges of the Rocky Mountains. This geographical fact is reflected in the state's name,...

; Leadville, Colorado

Colorado

Colorado is a U.S. state that encompasses much of the Rocky Mountains as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains...

; and Organ Mountains

Organ Mountains

The Organ Mountains are a rugged mountain range in southern New Mexico in the Southwestern United States. They lie east of the city of Las Cruces, in Doña Ana County.-Geography:...

, New Mexico

New Mexico

New Mexico is a state located in the southwest and western regions of the United States. New Mexico is also usually considered one of the Mountain States. With a population density of 16 per square mile, New Mexico is the sixth-most sparsely inhabited U.S...

 in the United States; and in several localities in North Africa

North Africa

North Africa or Northern Africa is the northernmost region of the African continent, linked by the Sahara to Sub-Saharan Africa. Geopolitically, the United Nations definition of Northern Africa includes eight countries or territories; Algeria, Egypt, Libya, Morocco, South Sudan, Sudan, Tunisia, and...

. Further hemimorphite occurrences are the Padaeng deposit near Mae Sod in western Thailand

Thailand

Thailand , officially the Kingdom of Thailand , formerly known as Siam , is a country located at the centre of the Indochina peninsula and Southeast Asia. It is bordered to the north by Burma and Laos, to the east by Laos and Cambodia, to the south by the Gulf of Thailand and Malaysia, and to the...

; Sardinia

Sardinia

Sardinia is the second-largest island in the Mediterranean Sea . It is an autonomous region of Italy, and the nearest land masses are the French island of Corsica, the Italian Peninsula, Sicily, Tunisia and the Spanish Balearic Islands.The name Sardinia is from the pre-Roman noun *sard[],...

; Nerchinsk

Nerchinsk

Nerchinsk is a town and the administrative center of Nerchinsky District of Zabaykalsky Krai, Russia, located east of Lake Baikal, east of Chita, and about west of the Chinese border on the left bank of the Nercha River, above its confluence with the Shilka River, which flows into the Amur...

, Siberia

Siberia

Siberia is an extensive region constituting almost all of Northern Asia. Comprising the central and eastern portion of the Russian Federation, it was part of the Soviet Union from its beginning, as its predecessor states, the Tsardom of Russia and the Russian Empire, conquered it during the 16th...

; Cave del Predil

Cave del Predil

Cave del Predil is a is a frazione subdivision of the comune of Tarvisio in the Province of Udine, in the Friuli-Venezia Giulia region of northeastern Italy...

, Italy

Italy

Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...

; Bleiberg, Carinthia

Carinthia (state)

Carinthia is the southernmost Austrian state or Land. Situated within the Eastern Alps it is chiefly noted for its mountains and lakes.The main language is German. Its regional dialects belong to the Southern Austro-Bavarian group...

, Austria

Austria

Austria , officially the Republic of Austria , is a landlocked country of roughly 8.4 million people in Central Europe. It is bordered by the Czech Republic and Germany to the north, Slovakia and Hungary to the east, Slovenia and Italy to the south, and Switzerland and Liechtenstein to the...

; Matlock, Derbyshire

Derbyshire

Derbyshire is a county in the East Midlands of England. A substantial portion of the Peak District National Park lies within Derbyshire. The northern part of Derbyshire overlaps with the Pennines, a famous chain of hills and mountains. The county contains within its boundary of approx...

, England.