All About Diamonds

✦ A blue, boron-bearing diamond, with dark inclusions of a mineral called ferropericlase that was one of 26 inclusion-containing blue diamoids examined as part of a study of about 1000 blue diamonds (see: Smith, E. M., Shirey, S. B., Richardson S. H., Nestola, F., Bullock, E. S., Wang, J., & Wang, W. (2018) Blue boron-bearing diamonds from Earth’s lower mantle. Nature, 560 (7716), 84–87. http://doi.org/10.1038/s41586-018-0334-5). This gem weighs 0.03 carats. (Photo: Evan M. Smith/© 2018 GIA).

Everything you want to know about diamonds (for the specialist):

Smit, K.V., Shirey, S.B., Pearson, D.G., Stachel, T., Nestola, F., and Moses, T. eds. (2022) Diamond: Genesis, Mineralogy, and Geochemistry. Reviews in Mineralogy and Geochemistry v88, Mineralogical Society of America, Chantilly, VA. i-xvi + 876 pages. ISBN 978-1-946850-10-2


Here's a general review of the geological aspects of diamond formation:

Shirey, S.B., and Shigley, J.E., 2013, Recent advances in understanding the geology of diamonds: Gems & Gemology, v. 49, 188–222. http://dx.doi.org/10.5741/GEMS.49.4.188


How do most diamonds form?

Smit, K. V. and Shirey, S.B. (2018) How do diamonds form in the deep Earth? Gems & Gemology 54: 440–445. https://www.gia.edu/gems-gemology/winter-2018-how-do-diamonds-form-in-the-deep-earth


How do big diamonds form deep in the mantle?

Smith, E. M., Shirey, S. B. & Wang, W. (2017) The very deep origin of the world's biggest diamonds. Gems & Gemology, Vol. 53, No. 4, pp. 388–403. https://www.gia.edu/gems-gemology/winter-2017-worlds-biggest-diamonds


How does water cycle into the deep Earth based on diamonds?

Smit, K. V. and Shirey, S. B.​ (2018) Diamonds help solve the enigma of Earth's deep water, Gems & Gemology, Vol. 54 (no. 2) 220-223. https://www.gia.edu/doc/Summer-2018-Gems-Gemology.pdf


How do diamonds get to the surface?

Smit, K. V. and Shirey, S.B. (2019) Kimberlites: Earth’s Diamond Delivery System. Gems & Gemology 55: 270-276. https://www.gia.edu/gems-gemology/summer-2019-kimberlites-earths-diamond-delivery-system


How old are diamonds (e.g. dating diamonds)?

Smit, K.V., Timmerman, S., Aulbach, S., Shirey, S.B., Richardson, S.H., Phillips, D., and Pearson, D.G. (2022) Geochronology of Diamonds. in Smit, K.V., Shirey, S.B., Pearson, D.G., Stachel, T., Nestola, F., and Moses, T. eds. Diamond: Genesis, Mineralogy, and Geochemistry. Reviews in Mineralogy and Geochemistry 88 567–636. https://doi.org/10.2138/rmg.2022.88.11

Smit, K. V. and Shirey, S.B. (2019) How Old Are Diamonds? Are They Forever? Gems & Gemology 55: 102–109. https://www.gia.edu/gems-gemology/spring-2019-how-old-are-diamonds-are-they-forever

Pearson, D.G., and Shirey, S.B., 1999, Isotopic dating of diamonds, in Lambert David, D., and Ruiz, J., eds., Application of radiogenic isotopes to ore deposit research and exploration., Volume 12: Reviews in Economic Geology: Boulder, CO, United States, Society of Economic Geologists, p. 143-171.


What happens to diamonds during transport to Earth's surface and eruption?

Smit, K. V. and Shirey, S.B. (2020) Diamonds are not forever! Diamond dissolution. Gems & Gemology 56: 148–155. https://www.gia.edu/gems-gemology/spring-2020-diamond-dissolution


What were some of the Advances in diamond research made with the Deep Carbon Observatory (DCO) from 2011-2019?

Shirey, S., Smit, K., Pearson, D., Walter, M., Aulbach, S., Brenker, F. E., Bureau, H., Burnham, A. D., Cartigny, P., Chacko, T., Frost, D. J. , Hauri, E. H., Jacob, D. E., Jacobsen, S. D., Kohn, S. C., Luth, R. W., Mikhail, S., Navon, O., Nestola, F., Nimis, P., Smith, E. M., Stachel, T., Stagno, V., Steele, A., Thomassot, E., Thomson, A. R., Weiss, Y. (2019). Diamonds and the Mantle Geodynamics of Carbon: Deep Mantle Carbon Evolution from the Diamond Record. In B. Orcutt, I. Daniel, & R. Dasgupta (Eds.), Deep Carbon: Past to Present (pp. 89-128). Cambridge: Cambridge University Press. doi:10.1017/9781108677950.005. https://www.cambridge.org/core/books/deep-carbon/diamonds-and-the-mantle-geodynamics-of-carbon/E46212484DDAA32B1DA14B796EB3D9BC


A decade old summary of scientific research on diamonds (for the specialist):

Shirey, S.B., Cartigny, P., Frost, D.J., Keshav, S., Nestola, F., Nimis, P., Pearson, D.G., Sobolev, N.V., and Walter, M.J. (2013) Diamonds and the Geology of Mantle Carbon: Reviews in Mineralogy and Geochemistry, v. 75, p. 355–421. http://doi.org/10.2138/rmg.2013.75.12


Diamonds as a mantle sample —what was the state of the art in 2003?

Pearson, D.G., Canil, D., and Shirey, S.B. (2003) Chapter 7 - Mantle samples included in volcanic rocks: xenoliths and diamonds, in Carlson, R.W., ed., Teatise On Geochemistry: Vol. 2, The Mantle: New York, Elsevier, p. 171-277. https://www.sciencedirect.com/science/article/pii/B0080437516020053?via%3Dihub