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Showing results for tags 'la cumbre mine'.
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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