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Showing results for tags 'hymenaea'.
Found 14 results
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VIDEO: Chiapas Amber (La Quinta Fm./Mazantic Shale, 22.8-15 Ma)
Barrelcactusaddict posted a gallery image in Member Collections
From the album: Fossil Amber and Copal: Worldwide Localities
Chiapas Amber Simojovel, Chiapas, Mexico La Quinta Fm./Mazantic Shale (Simojovel Group) 22.8-15 Ma Specimen (Rough): Weight: 11.8g Dimensions: 33x31x17mm Lighting: 140lm LED Longwave UV (365nm) About the Specimen: A thick, red oxidized layer was formed over millions of years through oxidation during the amber's burial. The blue-green fluorescence is due to exposure of the amber's hydrocarbons to UV wavelengths in the LED light. There are numerous fossil barnacles and barnacle scars, coating the exterior of the specimen. History: The amber of Chiapas has a history of use that dates back to the age of the Maya Empire; amber was traded between different tribes, and sometimes sent as an annual tribute to other nations (i.e., Aztec Empire). It was frequently fashioned into ornaments and jewelry such as necklaces, as well as lip, nose, and ear plugs; living descendants of the Mayan civilization carry on this ancient tradition, and skilled artisans fashion amber into similar jewelry, and sculptures of intricate detail. Botanical Source: Through Carbon-13 Nuclear Magnetic Resonance Spectroscopy, as well as the presence of fossil leaves and flowers, the source trees of Chiapas amber have been identified as two extinct species belonging to the Hymenaea genus (Subfamily: Caesalpinioideae): H. mexicana and H. allendis; both trees are related to H. protera, which produced Dominican amber. The closest living relative of these three extinct genera is H. verrucosa, which is native to East Africa. Geology of Deposits: The Sierra Madre del Sur contains three amber-bearing Formations, beginning at the youngest: Balumtun Sandstone, Mazantic Shale, and La Quinta Fm.; amber is most frequently found in the Mazantic Shale and La Quinta Formations, and is associated with layers of lignite, and found in calcareous marine sandstones, siltstones, and shales. Amber specimens up to 60cm long are known to occur at the Campo La Granja mines. Sources: “Amber From Chiapas: A Gem With History”; Universidad Nacional Autónoma de México, Voices of Mexico, No. 72; Lynneth S. Lowe 2005 “Mexican amber history”; Mayan Copal (website blog), March 29, 2018 “Early Miocene amber inclusions from Mexico reveal antiquity of mangrove-associated copepods”; Scientific Reports, Issue 6; Rony Huys, et. al. 2016 “Hymenaea mexicana sp. nov. (Leguminosae: Caesalpinioideae) from Mexican amber indicates Old World connections”; Botanical Journal of the Linnean Society, Issue 139, pp. 125-132; George Poinar Jr., Alex E. Brown 2002© Kaegen Lau
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Ethiopian Amber (Debre Libanos Sandstone; 23-16 Ma)
Barrelcactusaddict posted a gallery image in Member Collections
From the album: Fossil Amber and Copal: Worldwide Localities
4.7g polished specimen of amber from one of several deposits near Alem Ketema, Amhara Region, Ethiopia; piece measures 35x24x17mm. There is a thin vein of transparent material, while the rest is heavily included with organic detritus; some small fragments of plant material are seen in the transparent portions (see associated photo). The green coloration is partly due to the amber's autofluorescence initiated by the LED light (transmitted) during photography; the clear portions of this specimen present a yellow-green base color in incandescent light, and emit a greenish fluorescence in sunlight or LED light. Ethiopian amber deposits have been described relatively recently (2010), and the amber occurring in the siltstone layer of the Debre Libanos Sandstone was initially believed to be Cretaceous in age; later studies have proven the initial determination to be false, and further study of palynomorph and insect inclusions have provided a new estimated age of Early Miocene. The amber-bearing layer is over- and underlain by basaltic layers, some of which display columnar jointing; volcanic-derived pressure and heat has naturally changed the base color of some of this amber to varying shades of green. This amber is also believed to possibly have been produced by a member of the Hymenaea genus.© Kaegen Lau
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Ethiopian Amber (Debre Libanos Sandstone; 23-16 Ma)
Barrelcactusaddict posted a gallery image in Member Collections
From the album: Fossil Amber and Copal: Worldwide Localities
4.7g polished specimen of amber from one of several deposits near Alem Ketema, Amhara Region, Ethiopia; piece measures 35x24x17mm. This view of the specimen displays organic detritus inclusions: in particular, a long fibrous subject (at center, beneath fluorescent layer) can be seen. The green coloration is partly due to the amber's autofluorescence initiated by the LED light (transmitted) during photography; the clear portions of this specimen present a yellow-green base color in incandescent light, and emit a greenish fluorescence in sunlight or LED light. Ethiopian amber deposits have been described relatively recently (2010), and the amber occurring in the siltstone layer of the Debre Libanos Sandstone was initially believed to be Cretaceous in age; later studies have proven the initial determination to be false, and further study of palynomorph and insect inclusions have provided a new estimated age of Early Miocene. The amber-bearing layer is over- and underlain by basaltic layers, some of which display columnar jointing; volcanic-derived pressure and heat has naturally changed the base color of some of this amber to varying shades of green. This amber is also believed to possibly have been produced by a member of the Hymenaea genus.© Kaegen Lau
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Dominican Amber (La Toca Fm., 20.43-13.65 Ma)
Barrelcactusaddict posted a gallery image in Member Collections
From the album: Fossil Amber and Copal: Worldwide Localities
4.7g piece of amber from the La Cumbre Mine, measuring (mm) 25x22x15. It has a couple marcasite inclusions: seen here is a protruding portion (one half remains inside the piece) that was perhaps a gas bubble, but later infiltrated with iron and sulfur in solution during burial, migrating via a fracture/microfracture; or it may be a permineralized organic/inorganic inclusion (shell, quartz pebble, etc.), which are documented in amber from the La Cumbre deposit, and is called "double fossilization": while this occurs in tiny grains of younger La Cumbre amber which were deposited after the older amber seen here, it is possible it is seen in this older La Cumbre material. Another example of double fossilization is known from fully pyritized insects with marcasite interiors, recorded from cretaceous amber in NW France. There are dozens of visible dual-phase, countless single-phase, and at least two triple-phase bubbles. "Pyrite disease" is a major concern with this specimen; even with preservation in an airtight container, oxidation is still possible, given the presence of gas/liquid inclusions, and the fact that water and gases do penetrate and migrate within amber over time. Portions of the piece may be doomed, but it is interesting while it lasts.© Kaegen Lau
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Dominican Amber (La Toca Fm., 20.43-13.65 Ma)
Barrelcactusaddict posted a gallery image in Member Collections
From the album: Fossil Amber and Copal: Worldwide Localities
5.4g piece of amber from the La Cumbre Mine, measuring (mm) 28x24x18. It has a couple marcasite inclusions: visible here, is a protruding portion (one half remains inside the piece) that was perhaps a gas bubble, but later infiltrated with iron and sulfur in solution, via a natural fracture/microfracture; the other is a natural fracture viewable on the opposite side, infiltrated and completely coated by marcasite: the thin film that begins at the rough, unbroken exterior (underside of specimen in picture). There are dozens of visible dual-phase, countless single-phase, and at least two triple-phase bubbles. These are easily seen in the other four related photos of the finished specimen. "Pyrite disease" is a major concern with this specimen; even with preservation in an airtight container, oxidation is still possible, given the presence of gas/liquid inclusions, and the fact that water and gases do penetrate and migrate within amber over time. Portions of the piece may be doomed, but it is interesting while it lasts.© Kaegen Lau
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Dominican Amber (La Toca Fm., 20.43-13.65 Ma)
Barrelcactusaddict posted a gallery image in Member Collections
From the album: Fossil Amber and Copal: Worldwide Localities
Triple-phase inclusion and a few in-focus single and dual-phase inclusions nearby. The triple-phase bubble is a narrow chamber, possibly part of a methane termite (incomplete, heavily oxidized); there are two organic solids, the larger preventing the migration of the gas bubble. These inclusions are contained within the 5.4-4.7g specimen depicted in the four related photos. This image was captured using a Samsung WB35F while holding a BelOMO 10x loupe between the lens and specimen.© Kaegen Lau
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Dominican Amber (La Toca Fm., 20.43-13.65 Ma)
Barrelcactusaddict posted a gallery image in Member Collections
From the album: Fossil Amber and Copal: Worldwide Localities
Triple-phase inclusion (center right) and over twelve, viewable dual-phase inclusions nearby. The triple-phase bubble contains movable particulates, which are slightly visible here in the lower-half portion of the bubble. These inclusions are contained within the 5.4-4.7g specimen depicted in the four related photos. This crude image was captured using a Samsung WB35F while holding a BelOMO 10x loupe between the lens and specimen.© Kaegen Lau
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Dominican Amber (La Toca Fm., 20.43-13.65 Ma)
Barrelcactusaddict posted a gallery image in Member Collections
From the album: Fossil Amber and Copal: Worldwide Localities
4.7g piece of amber from the La Cumbre Mine, measuring (mm) 25x22x15. Seen at the base of the specimen is a natural fracture that was infiltrated and completely coated by marcasite during the resin's diagenesis, in a thin film that began at the previously rough, unbroken exterior (underside of specimen in picture). There are dozens of visible dual-phase, countless single-phase, and at least two triple-phase bubbles. These are easily seen in the other four related photos of the finished specimen. "Pyrite disease" is a major concern with this specimen; even with preservation in an airtight container, oxidation is still possible, given the presence of gas/liquid inclusions, and the fact that water and gases do penetrate and migrate within amber over time. Portions of the piece may be doomed, but it is interesting while it lasts.© Kaegen Lau
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Dominican Amber (La Toca Fm., 20.43-13.65 Ma)
Barrelcactusaddict posted a gallery image in Member Collections
From the album: Fossil Amber and Copal: Worldwide Localities
5.4g piece of amber from the La Cumbre Mine, measuring (mm) 28x24x18. Visible here, is a natural fracture that was infiltrated and completely coated by marcasite during the resin's diagenesis, in a thin film that begins at the rough, unbroken exterior (underside of specimen in picture). There are dozens of visible dual-phase, countless single-phase, and at least two triple-phase bubbles. These are easily seen in the other four related photos of the finished specimen. "Pyrite disease" is a major concern with this specimen; even with preservation in an airtight container, oxidation is still possible, given the presence of gas/liquid inclusions, and the fact that water and gases do penetrate and migrate within amber over time. Portions of the piece may be doomed, but it is interesting while it lasts.© Kaegen Lau
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Dominican Amber (La Toca Fm., 20.43-13.65 Ma)
Barrelcactusaddict posted a gallery image in Member Collections
From the album: Fossil Amber and Copal: Worldwide Localities
Opposing view of same specimen from associated image, weighing 10.0g and measuring (mm) 40x31x20; note the rough, unaltered (i.e., unbroken, natural) exterior of the specimen. Most dominican amber is transparent to translucent, yet this specimen is more akin in appearance to the "butterscotch" variety of Baltic amber; I have not determined if the turbidity is due to microscopic air bubbles, or organic inclusions, though it is most likely the former. This type of dominican amber is sometimes seen as a thin layer/flow overlying transparent material, but this specimen is mostly whole, and it's unaltered exterior does not indicate to its having overlain any previous flows. I uncovered this piece while cleaning a 2kg lot of mine-direct material (La Cumbre Mine).© Kaegen Lau
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Dominican Amber (La Toca Fm., 20.43-13.65 Ma)
Barrelcactusaddict posted a gallery image in Member Collections
From the album: Fossil Amber and Copal: Worldwide Localities
Small run of amber from the La Cumbre Mine, weighing 2.4g, and measuring (mm) 37x13x8. It consists of numerous successive flows, and contains several small single-phase bubbles; as this specimen does, several others I have (from the same 2kg lot) from this locality also display an interesting "schiller" effect when adjusted in-hand (light reflects off of the flow lines' surface). Biological inclusions are a possibility with this specimen, though I will need to prepare it to confirm this.© Kaegen Lau
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Dominican Amber (La Toca Fm., 20.43-13.65 Ma)
Barrelcactusaddict posted a gallery image in Member Collections
From the album: Fossil Amber and Copal: Worldwide Localities
Small run of amber from the La Cumbre Mine, weighing 2.4g, and measuring (mm) 37x13x8. It consists of numerous successive flows, and contains several small single-phase bubbles; biological inclusions are possible, though I will need to prepare the piece to confirm this.© Kaegen Lau
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Dominican Amber (La Toca Fm., 20.43-13.65 Ma)
Barrelcactusaddict posted a gallery image in Member Collections
From the album: Fossil Amber and Copal: Worldwide Localities
Dominican amber from the La Cumbre Mine, from the Cordillera Septentrional. Most pieces range from 5-10g in weight, with at least one containing a large two-phase inclusion (enhydro). Material from this mine frequently presents exterior crusts/aggregates of pyrite (iron sulfide); these were likely formed in a reducing, marine/lacustrine environment, where marine sediments, organic detritus, volcanic material (i.e., ash), and sulfate-reducing bacteria helped to provide the sulfides and iron needed.© Kaegen Lau
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Dominican Amber (La Toca Fm., 20.43-13.65 Ma)
Barrelcactusaddict posted a gallery image in Member Collections
From the album: Fossil Amber and Copal: Worldwide Localities
A rare and very unusual specimen, weighing 10.0g and measuring (mm) 40x31x20. Most dominican amber is transparent to translucent, yet this specimen is more akin in appearance to the "butterscotch" variety of Baltic amber; I have not determined if the turbidity is due to microscopic air bubbles, or organic inclusions, though it is most likely the former. This type of dominican amber is sometimes seen as a thin layer/flow overlying transparent material, but this specimen is mostly whole, and it's unaltered exterior does not indicate to its having overlain any previous flows. I uncovered this piece while cleaning a 2kg lot of mine-direct material.© Kaegen Lau
