Laponite is a synthetic smectite clay invented in 1962 by clay scientist

Barbara Neumann Barbara Zsusanna Neumann (; 30 November 1914 – 25 November 2002) was a Hungarian mineralogist and clay scientist who invented the chemical synthesis, synthetic clay laponite. In 2022, the Mineralogical Society of Great Britain and Ireland name ...

. Usually produced as powder, laponite is a

nanomaterial Nanomaterials describe, in principle, chemical substances or materials of which a single unit is sized (in at least one dimension) between 1 and 100 nm (the usual definition of nanoscale). Nanomaterials research takes a materials science ...

made up of very small disk-shaped crystals used in multiple industrial applications. Laponite was first marketed by the company

Laporte plc Laporte plc was a leading British chemicals business that operated from 1888 to 2000. It was listed on the London Stock Exchange and was a constituent of the FTSE 100 Index. History The Company was founded by Bernard Laporte, a German Chemist, in ...

and is currently produced by

BYK Additives & Instruments BYK is a globally operating supplier of additives and measuring instruments. The areas of application of BYK additives include the coatings, inks, plastics and oil/gas industries, the manufacture of care products, the manufacture of adhesives and ...

. Laponite is not an approved

mineral In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid substance with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. (2011): Mi ...

species, since it is not naturally occurring and it is not produced by geological processes. In the first formulation of laponite created by Neumann in 1962, the synthetic clay was determined to be a fluorohectorite and was produced in the form of discs 1 nanometer thick and with a diameter of 60 to 80 nanometers. This went into mass production in 1964. The mineral structure of the clay gives laponite its particular physical characteristics and is similar to the

smectite group A smectite (; ; ) is a mineral mixture of various swelling sheet silicates (phyllosilicates), which have a three-layer 2:1 (TOT) structure and belong to the clay minerals. Smectites mainly consist of montmorillonite, but can often contain secon ...

of clay minerals, with a 2:1 layered crystal structure in which two tetrahedral silica sheets lie either side of an octahedral sheet containing magnesium ions. In 1966, Neumann patented a second formulation of laponite, called 'Laponite RD'. This form was free from fluorine, and has subsequently become the most widely used form of laponite. This form of laponite has an empirical formula of . In later years, Neumann also created other variants of laponite including a lithium-free magnesium silicate clay, a form of synthetic

stevensite Stevensite is a white clay mineral composed of hydrated calcium, sodium and magnesium silicate, with the chemical formula (Ca,Na)xMg3-x(Si4O10)(OH)2. The mineral is a member of smectite A smectite (; ; ) is a mineral mixture of various swe ...

, and an iron silicate clay, which was a synthetic form of

nontronite Nontronite is the iron(III) rich member of the smectite group of clay minerals. Nontronites typically have a chemical composition consisting of more than ~30% Fe2 O3 and less than ~12% Al2O3 (ignited basis). Nontronite has very few economic dep ...

References

{{reflist Clay Smectite group Nanomaterials Synthetic minerals Products introduced in 1962