Paul Niggli (26 June 1888 – 13 January 1953) was a

Swiss Swiss most commonly refers to: * the adjectival form of Switzerland * Swiss people Swiss may also refer to: Places * Swiss, Missouri * Swiss, North Carolina * Swiss, West Virginia * Swiss, Wisconsin Other uses * Swiss Café, an old café located ...

mineralogist Mineralogy is a subject of geology specializing in the scientific study of the chemistry, crystal structure, and physical (including optical mineralogy, optical) properties of minerals and mineralized artifact (archaeology), artifacts. Specific s ...

, and

petrologist Petrology () is the branch of geology that studies rocks, their mineralogy, composition, texture, structure and the conditions under which they form. Petrology has three subdivisions: igneous, metamorphic, and sedimentary petrology. Igneous an ...

who was a leader in the field of

X-ray crystallography X-ray crystallography is the experimental science of determining the atomic and molecular structure of a crystal, in which the crystalline structure causes a beam of incident X-rays to Diffraction, diffract in specific directions. By measuring th ...

Education and career

Niggli was born in

Zofingen Zofingen () is a city in the canton of Aargau in Switzerland. It is the capital of the district of Zofingen. Zofingen is a walled city and home to an ancient monastic settlement. History In ancient times Zofingen was a settlement of the Celtic ...

and studied at the Swiss Federal Institute of Technology (ETH) in

Zürich Zurich (; ) is the list of cities in Switzerland, largest city in Switzerland and the capital of the canton of Zurich. It is in north-central Switzerland, at the northwestern tip of Lake Zurich. , the municipality had 448,664 inhabitants. The ...

and the

University of Zurich The University of Zurich (UZH, ) is a public university, public research university in Zurich, Switzerland. It is the largest university in Switzerland, with its 28,000 enrolled students. It was founded in 1833 from the existing colleges of the ...

, where he obtained a doctorate. His 1919 book, ''Geometrische Kristallographie des Diskontinuums'', played a seminal role in the refinement of

space group In mathematics, physics and chemistry, a space group is the symmetry group of a repeating pattern in space, usually in three dimensions. The elements of a space group (its symmetry operations) are the rigid transformations of the pattern that ...

theory. In this book, Niggli demonstrated that although X-ray reflection conditions do not always uniquely determine the

to which a crystal belongs, they do reveal a small number of possible space groups to which it could belong. Niggli used morphological methods to account for internal structure and, in his 1928 ''Kristallographische und Strukturtheoretische Grundbegriffe,'' he took up what is essentially the reverse process, the task of establishing the connection between space lattices and external crystal morphology. The great aim of his life was to integrate the whole field of

Earth science Earth science or geoscience includes all fields of natural science related to the planet Earth. This is a branch of science dealing with the physical, chemical, and biological complex constitutions and synergistic linkages of Earth's four spheres ...

s. In 1920, Niggli became the lead scientist at the ETH's ''Institut für Mineralogie und Petrographie'', where he brought his systematic approach to the study of crystal morphologies using

X-ray diffraction X-ray diffraction is a generic term for phenomena associated with changes in the direction of X-ray beams due to interactions with the electrons around atoms. It occurs due to elastic scattering, when there is no change in the energy of the waves. ...

. In 1935, Niggli and his doctoral student Werner Nowacki (1909–1988) determined the 73 three-dimensional arithmetic crystal classes ( symmorphic space groups). Niggli retired from the Institute in 1949. He was also professor of mineralogy at the ETH Zurich and at the University of Zurich. Niggli succeeded Paul Heinrich von Groth (1843–1927) as editor of ''

Zeitschrift für Kristallographie A magazine is a periodical publication, print or digital, produced on a regular schedule, that contains any of a variety of subject-oriented textual and visual content forms. Magazines are generally financed by advertising, purchase price, p ...

''.

Honors and awards

In 1948, Niggli was awarded the

Roebling Medal The Roebling Medal is the highest award of the Mineralogical Society of America for scientific eminence as represented primarily by scientific publication of outstanding original research in mineralogy. The award is named for Colonel Washington A. ...

of the

Mineralogical Society of America The Mineralogical Society of America (MSA) is a scientific membership organization. MSA was founded in 1919 for the advancement of mineralogy, crystallography, geochemistry, and petrology, and promotion of their uses in other sciences, industry, ...

. Since 1988 th
Paul Niggli Foundation
awards medals to outstanding Swiss mineral scientists below the age of 35 with a strong perspective for an academic career. Dorsum Niggli on the

Moon The Moon is Earth's only natural satellite. It Orbit of the Moon, orbits around Earth at Lunar distance, an average distance of (; about 30 times Earth diameter, Earth's diameter). The Moon rotation, rotates, with a rotation period (lunar ...

was named after him.

Personal life

Niggli married Hedwig Dübendorfer (later Hedwig Niggli) in 1915. He had two children with her, Ernst Niggli and Hedi Fritz-Niggli.

Bibliography

* * * * * *

References

1888 births 1953 deaths Petrologists Swiss mineralogists Academic staff of ETH Zurich ETH Zurich alumni People from Zofingen Academic staff of the University of Tübingen Academic staff of Leipzig University University of Zurich alumni Academic staff of the University of Zurich Crystallographers {{geologist-stub