Learn · Geologic record

Two continents, one origin

Education only. Carbonado’s origin is unresolved and debated. Nothing on these pages describes, or is connected to, any Luxurious Specimens lot. No lot is claimed to be carbonado or to come from space.

The Atlantic between Brazil and Africa today, seen by NASA's DSCOVR EPIC camera on June 18, 2020. Credit: NASA Earth Observatory image by Joshua Stevens, using imagery from the Deep Space Climate Observatory (DSCOVR). Source (NASA, public domain).

The two known carbonado regions lie on ancient blocks of crust: the São Francisco craton in Brazil and the Congo craton in Africa. GIA notes they shared one geological setting for more than a billion years^[1].

Geologists reconstruct them as one block, joined by a “São Francisco–Congo cratonic bridge” that stayed intact from about two billion years ago until the Cretaceous, when the Atlantic rift cut through it^[2]. Gondwana began breaking apart about 180 million years ago^[1], and seafloor spreading in the South Atlantic began in the south around 135–130 million years ago^[3,4].

Florida has its own Gondwanan link: its deep basement, the Suwannee terrane, is Gondwanan rock that formed near the West African and/or Amazonian cratons and joined North America when Pangaea assembled^[5,6]. ASA Digital Art’s theory: material like carbonado could have been reworked over a very long time into South Florida’s young, Pleistocene limestone^[7]; this is our own untested idea. Carbonado is published as known only from Brazil and the Central African Republic^[1]. ASA Digital Art’s specimens are not identified as carbonado. No origin, space or otherwise, is claimed for any ASA Digital Art specimen or Luxurious Specimens lot.

That shared history is why some researchers, including Haggerty, link the two deposits to a single source^[8,9]. The joined continents are well established; whether the stones arrived from space is not.

Illustration (digital render): eastern South America and west-central Africa fitted together, as they were before the South Atlantic opened. Artistic, not a scientific map.

Illustration (digital render): South America and Africa drifting apart as the South Atlantic opens. Artistic, not to scale; modern coastlines shown.

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Sources

Gems & Gemology (GIA), Summer 2017, “Carbonado Diamond: A Review of Properties and Origin.” https://www.gia.edu/gems-gemology/summer-2017-carbonado-diamond
Alkmim, F. F. et al. (2006). Kinematic evolution of the Araçuaí-West Congo orogen in Brazil and Africa: Nutcracker tectonics during the Neoproterozoic assembly of Gondwana. Precambrian Research. https://www.sciencedirect.com/science/article/abs/pii/S0301926806001483
“The late rifting phase and continental break-up of the southern South Atlantic” (2016). Geological Society, London, Special Publications 420. https://doi.org/10.1144/sp420.2
“A new scheme for the opening of the South Atlantic Ocean and the dissection of an Aptian salt basin” (2009). Geophysical Journal International. https://doi.org/10.1111/j.1365-246x.2009.04137.x
Mueller, P. A., Heatherington, A. L., Wooden, J. L., Shuster, R. D., Nutman, A. P. & Williams, I. S. (1994). Precambrian zircons from the Florida basement: A Gondwanan connection. Geology 22, 119–122 (USGS Publications Warehouse record). https://pubs.usgs.gov/publication/70187227
Mueller, P. A., Heatherington, A. L., Foster, D. A., Thomas, W. A. & Wooden, J. L. (2014). The Suwannee suture: Significance for Gondwana–Laurentia terrane transfer and formation of Pangaea. Gondwana Research 26(1), 365–373. https://doi.org/10.1016/j.gr.2013.06.018
Johnson, R. A. (1993). Stratigraphy of the Upper Pleistocene Miami Limestone of Florida. Geological Society of America Abstracts with Programs (conference abstract, not peer-reviewed), via OSTI. https://www.osti.gov/biblio/6112329
New Scientist, “Rare black diamonds may have come from space.” https://www.newscientist.com/article/1900370-rare-black-diamonds-may-have-come-from-space/
Discover Magazine, “Diamonds From Outer Space” (interview reporting Haggerty's single-asteroid view). https://www.discovermagazine.com/60-diamonds-from-outer-space-11985

Image credits

Background: Cassiopeia A (NIRCam image), weic2330a. Credit: NASA, ESA, CSA, STScI, D. Milisavljevic (Purdue University), T. Temim (Princeton University), I. De Looze (University of Gent). Source (CC BY 4.0).
How the continents moved from Pangaea (250 million years ago) to today: U.S. Geological Survey, This Dynamic Earth: The Story of Plate Tectonics. Source (USGS, public domain).
Southern Florida’s Everglades: NASA Earth Observatory images by Jesse Allen, using Landsat data from the U.S. Geological Survey. Source (NASA, public domain).
Supernova 1987A: NASA, ESA, and R. Kirshner (Harvard-Smithsonian Center for Astrophysics and Gordon and Betty Moore Foundation) and P. Challis (Harvard-Smithsonian Center for Astrophysics). Source (CC BY 4.0).
Carbon-rich dust shells around the star Wolf-Rayet 140: NASA, ESA, CSA, STScI, E. Lieb (University of Denver), R. Lau (NSF NOIRLab), J. Hoffman (University of Denver). Source (CC BY 4.0).
Manicouagan Crater: NASA Earth Observatory image by Lauren Dauphin, using MODIS data from NASA EOSDIS LANCE and GIBS/Worldview. Source (NASA, public domain).
The Pilbara Craton in Western Australia (false color): NASA Earth Observatory image by Joshua Stevens, using data from NASA/METI/AIST/Japan Space Systems, and the U.S./Japan ASTER Science Team. Source (NASA, public domain).
The Atlantic between Brazil and Africa today: NASA Earth Observatory image by Joshua Stevens, using imagery from the Deep Space Climate Observatory (DSCOVR). Source (NASA, public domain).
Dzanga Bai: NASA Earth Observatory image by Lauren Dauphin, using Landsat data from the U.S. Geological Survey and data from OpenStreetMap (OSM map data © OpenStreetMap contributors, ODbL). Source (NASA, public domain; map data ODbL).
Skully photos (asa-specimen-01, 02, 03, 08 and asa-skully-scale): ASA Digital Art (own photos of one ASA specimen, Skully, under different lighting and angles; the scale photo is cropped with the scale branding blurred; not identified as carbonado; no origin is claimed; not a lot for sale).
Other specimen photos (asa-specimen-07, 09, 10): ASA Digital Art (own photos of ASA specimens, background removed; not identified as carbonado; no origin is claimed; not lots for sale).
Gravel photos (asa-gravel-04, 05, 06): ASA Digital Art (own photos of crushed sediment and gravel; no site named). Collected lawfully over about a decade as a personal hobby, on break and lunch time while working on construction projects, with authorization to remove non-building material that would otherwise have been thrown out or buried under pavement; not from any park, preserve or public land where collecting is restricted.
Red-hot images (asa-specimen-09-redhot, asa-specimen-10-redhot): Digitally edited illustration based on a photo of an ASA Digital Art specimen. The red-hot glow was added digitally to picture the plasma-channel idea; the specimen was not heated and does not look like this. Not identified as carbonado; no origin is claimed. Speculative. Made locally from ASA Digital Art photos.
Fossil tooth photo: ASA Digital Art (own photo of a fossil found with ASA specimens; appears to be a Megalodon tooth; not a lot for sale).
1200x microscope photo: ASA Digital Art (own photo of an ASA specimen; not identified as carbonado; not a lot).
Images labeled “Illustration (digital render)” are artwork made for this page. They are not photographs and do not show actual specimens or any lot.

ESA/Hubble and ESA/Webb images are used under CC BY 4.0. Use of these images does not imply endorsement by ESA, NASA, CSA or STScI. NASA images are public domain and credited as requested.