File:White & pink pearls (cultured) (31301996872).jpg
Original file (2,999 × 2,140 pixels, file size: 1.35 MB, MIME type: image/jpeg)
Captions
Summary[edit]
DescriptionWhite & pink pearls (cultured) (31301996872).jpg |
Cultured white & pink pearls (the long axis of the pearl at center is ~1.1 cm long) Pearls are spherical to subspherical to irregularly-shaped, biogenic concretions of slightly iridescent, nacreous aragonite (CaCO3 - calcium carbonate). Pearls are principally made by pearl oysters (Animalia, Mollusca, Bivalvia). Natural pearls are scarce. Well-formed, spherical natural pearls are rare. Fossil pearls are known, but are also scarce. "Mother of pearl" is relatively common - the same material in pearls occurs in the actual shells of some bivalves. Well-known pearl oysters include Pinctada margaritifera (the black-lipped pearl oyster), Pinctada fucata (the Japanese pearl oyster), and Pinctada maxima (the gold-lipped pearl oyster). Mother-of-pearl is well developed in shells of other species such as Pinctada imbricata (Atlantic pearl oyster), Pteria colymbus, Pteria penguin (both are winged pearl oysters), Haliotis spp. (abalones), and Atrina spp. (pen shells). Natural pearls form when foreign objects, such as sediment grains or other debris, enter a pearl oyster and get embedded in its mantle tissue. The particle is slowly coated with nacreous aragonite, which prevents the particle from causing disease or injury. The end result is a biogenic concretion called a pearl. Natural pearls show a concentric structure through the entire cross-section. Almost all commercially available pearls are semi-natural - they have been cultured. Cultured pearls have been available for many decades. A spherical bead is placed inside a pearl oyster, under its mantle tissue. The bead is slowly coated with nacreous aragonite to produce a cultured pearl, which shows concentric structure only in the outer portions of its cross-section. Marine pearls can be whitish, pinkish, yellowish, or blackish. Freshwater pearls are also known - natural examples vary from ~spherical to highly irregularly-shaped. Blister pearls are attached to the host mollusc's shell. |
Date | |
Source | White & pink pearls (cultured) |
Author | James St. John |
Licensing[edit]
- You are free:
- to share – to copy, distribute and transmit the work
- to remix – to adapt the work
- Under the following conditions:
- attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
This image was originally posted to Flickr by James St. John at https://flickr.com/photos/47445767@N05/31301996872 (archive). It was reviewed on 30 November 2019 by FlickreviewR 2 and was confirmed to be licensed under the terms of the cc-by-2.0. |
30 November 2019
File history
Click on a date/time to view the file as it appeared at that time.
Date/Time | Thumbnail | Dimensions | User | Comment | |
---|---|---|---|---|---|
current | 16:52, 30 November 2019 | 2,999 × 2,140 (1.35 MB) | Ser Amantio di Nicolao (talk | contribs) | Transferred from Flickr via #flickr2commons |
You cannot overwrite this file.
File usage on Commons
File usage on other wikis
The following other wikis use this file:
- Usage on no.wikipedia.org
Metadata
This file contains additional information such as Exif metadata which may have been added by the digital camera, scanner, or software program used to create or digitize it. If the file has been modified from its original state, some details such as the timestamp may not fully reflect those of the original file. The timestamp is only as accurate as the clock in the camera, and it may be completely wrong.
JPEG file comment | AppleMark |
---|