A lentoid is a geometric shape of a

three-dimensional In geometry, a three-dimensional space (3D space, 3-space or, rarely, tri-dimensional space) is a mathematical space in which three values (''coordinates'') are required to determine the position (geometry), position of a point (geometry), poi ...

body, best described as a circle viewed from one direction and a

convex lens A lens is a transmissive optical device that focuses or disperses a light beam by means of refraction. A simple lens consists of a single piece of transparent material, while a compound lens consists of several simple lenses (''elements'') ...

viewed from every orthogonal direction. It has no strict mathematical definition, but may be described as the volume enclosed within overlapping

paraboloid In geometry, a paraboloid is a quadric surface that has exactly one axial symmetry, axis of symmetry and no central symmetry, center of symmetry. The term "paraboloid" is derived from parabola, which refers to a conic section that has a similar p ...

s. The term is most often used in describing

jewelry Jewellery (or jewelry in American English) consists of decorative items worn for personal adornment such as brooches, ring (jewellery), rings, necklaces, earrings, pendants, bracelets, and cufflinks. Jewellery may be attached to the body or the ...

and cellular phenomena in

microbiology Microbiology () is the branches of science, scientific study of microorganisms, those being of unicellular organism, unicellular (single-celled), multicellular organism, multicellular (consisting of complex cells), or non-cellular life, acellula ...

In history

Since ancient times, the lentoid shape has been used to fashion

and seals for identification made from a variety of

gemstone A gemstone (also called a fine gem, jewel, precious stone, semiprecious stone, or simply gem) is a piece of mineral crystal which, when cut or polished, is used to make jewellery, jewelry or other adornments. Certain Rock (geology), rocks (such ...

s and metals. In

Minoan Crete The Minoan civilization was a Bronze Age culture which was centered on the island of Crete. Known for its monumental architecture and energetic art, it is often regarded as the first civilization in Europe. The ruins of the Minoan palaces at K ...

, for example,

Minoan seals Minoan seals are impression seals in the form of carved gemstones and similar pieces in metal, ivory and other materials produced in the Minoan civilization. They are an important part of Minoan art, and have been found in quantity at specific s ...

have been found with complex carving on lentoid stones. The lentoid shape was one of the most commonly recovered seal shapes from Minoan

Knossos Knossos (; , ; Linear B: ''Ko-no-so'') is a Bronze Age archaeological site in Crete. The site was a major centre of the Minoan civilization and is known for its association with the Greek myth of Theseus and the minotaur. It is located on th ...

on Crete dating to the

Bronze Age The Bronze Age () was a historical period characterised principally by the use of bronze tools and the development of complex urban societies, as well as the adoption of writing in some areas. The Bronze Age is the middle principal period of ...

, as evidenced by the finds at that

palace.

Gallery

File:Agate lentoid seal MET DP141655 DP141657.jpg, Lentoid Minoan seal in

agate Agate ( ) is a banded variety of chalcedony. Agate stones are characterized by alternating bands of different colored chalcedony and sometimes include macroscopic quartz. They are common in nature and can be found globally in a large number of d ...

: seal and impression File:Agate lentoid seal MET DP141656 (cropped).jpg, Side view of same seal

References

Jewellery Minoan art {{Geometry-stub

In history

Gallery

See also

References