NOTE: Closed captioning in English and Spanish available. Gems are revered throughout history for their natural beauty. They also serve as a time machine for our planet. In this talk, Ananya Mallik will discover how diamonds, jades, and rubies are studied to better understand the evolutions of Earth and how minerals can serve as an X-ray into the planet’s inner layers.

Watch the Diamond Session at PDAC2021, with three invited speakers: Karen Smit, Graham Pearson and Alexandrina Fulop. Every year, the Prospectors and Developers Association of Canada (PDAC) organises a large convention in for Mineral Exploration and Mining. The Diamond Session is organised by Pat Sheahan, Jennifer Pell and Brooke Clements.

Chemical geodynamics with eclogite. Mid-ocean ridge basalt (MORB), the melting product of the ambient convecting mantle, subducts at convergent margins. Some of this material returns to the surface as tectonically exhumed or xenolithic “oceanic” eclogite.Oceanic eclogite is a key indicator of past subduction and can also be used to investigate its source in the convecting mantle as far back as ~3 Ga. However, the eclogite record is obscured by seafloor weathering and processing in subduction zones. When samples that were metasomatised or derived from strongly differentiated or cumulate protoliths are excluded, V/Sc and Fe3+/ΣFe in eclogites are robust geochemical proxies of the oxygen fugacity (ƒO2) of the ambient mantle. Both ratios are higher in post-Archaean than in most Archaean eclogites, suggesting a secular increase in the convecting mantle’s ƒO2. The moderately incompatible elements, Ti and Sm, record the melt fraction by which the eclogites’ protoliths formed, and indirectly, the mantle potential temperature (TP). Their abundances increase through time, consistent with cooling, but require TP at 3 Ga only some 100-150°C higher than today. Extremely low 87Sr/86Sr (≤0.7007) in some eclogites suggests moderate depletion of ambient mantle by 3 Ga. These parameters (ƒO2, TP, composition) affect mantle dynamics and melting relations, plate strength and the redox state of volcanic gases, with strong impacts on the evolution of Earth and life.Oxybarometry also shows that after metamorphism, the vast majority of eclogites, including those showing evidence of seafloor weathering (non-mantle δ18O), record ƒO2 lower than both modern MORB and its Archaean equivalent. The low ƒO2 stabilises diamond relative to oxidised carbon species, presenting a pathway for deep carbon recycling, and indicating little oxidising power for deeply subducted oceanic crust.

April 29, 2021 | 6:30 PM EDT Presented by Dr.Graham Pearson (University of Alberta) Finding and evaluating diamond deposits is one of the hardest tasks in mineral resource development. In this talk, we will delve a little into the techniques used to find diamonds and how to evaluate the deposits. We will then examine why diamonds—the deepest derived of all natural materials—are unique in their ability to illuminate processes taking place over 700 km beneath Earth's surface, and up to 3.5 billion years back into its history. About the speaker: Dr. Graham Pearson is a former postdoc at the Earth and Planets Laboratory (then the Department of Terrestrial Magnetism) and the current Canada Excellence Research Chair at the University of Alberta. As one of the world's leading scientists in diamond studies, Dr. Pearson uses diamonds as a window into the Earth's past. He aims to understand the formation of diamond-forming roots beneath continents. His research is focused on the cratonic mantle lithosphere, kimberlites, and diamonds. Read more about Graham Pearson on his website.

March 5, 2021 l GSSA Lunchtime Lecture with Dr Tania Marshall A travelogue through the alluvial diamond deposits of Africa

This video is from the Research Track of the 2018 GIA International Gemological Symposium. The Research Track presented the latest findings by Institute researchers and scientists respected across the industry and from around the world. This presentation is part of the theme, Diamond Identification. Diamond is one of the most important and valuable gem minerals, and is widely subjected to treatment using different processes to improve the color and clarity of gems. The increasing presence of diamond treatments in the market is a significant issue for identification. Presentations may include, but are not limited to, identifying natural, treated and synthetic diamonds. To learn more about GIA, visit: https://www.gia.edu/ SUBSCRIBE TO OUR CHANNEL https://www.youtube.com/user/officialGIAchannel FOLLOW US Facebook: https://www.facebook.com/GIA4Cs Blog: http://4csblog.gia.edu/ Twitter: https://twitter.com/gianews Pinterest: https://www.pinterest.com/giapins/ Google Plus: https://plus.google.com/+OfficialGIAChannel4cs

This video is from the Research Track of the 2018 GIA International Gemological Symposium. The Research Track presented the latest findings by Institute researchers and scientists respected across the industry and from around the world. This presentation is part of the theme, Diamond Identification. Diamond is one of the most important and valuable gem minerals, and is widely subjected to treatment using different processes to improve the color and clarity of gems. The increasing presence of diamond treatments in the market is a significant issue for identification. Presentations may include, but are not limited to, identifying natural, treated and synthetic diamonds. To learn more about GIA, visit: https://www.gia.edu/ SUBSCRIBE TO OUR CHANNEL https://www.youtube.com/user/officialGIAchannel FOLLOW US Facebook: https://www.facebook.com/GIA4Cs Blog: http://4csblog.gia.edu/ Twitter: https://twitter.com/gianews Pinterest: https://www.pinterest.com/giapins/ Google Plus: https://plus.google.com/+OfficialGIAChannel4cs

On April 30, 2019, Professor Nathalie de Leon (Princeton University) presented the KNI Distinguished Seminar on "Engineering Coherent Defects in Diamond". Diamond's nitrogen vacancy (NV) center has been used to demonstrate basic building blocks of quantum networks and quantum computers. In her lecture, de Leon discusses point defects in diamond known as color centers that are a promising physical platform for engineering coherent systems. de Leon also examines current challenges with this material as well as recent advancements her team has made in surface processing and termination techniques. The KNI Distinguished Seminar Series is a series hosted by The Kavli Nanoscience Institute where eminent scientists and thinkers with strong yet varied backgrounds in nanoscience and nanotechnology share their expertise with the Caltech community. The scopes of presentations may range from: recent outstanding scientific highlights/technological advancements, to innovative early-stage research developments, to broader cross-disciplinary topics that are relevant to nanoscience. Each seminar is recorded and posted to the KNI YouTube channel.

Recorded from IQC's NanoMRI conference 2015. Ronald Walsworth of Harvard University describes progress in nanoscale magnetic imaging using Nitrogen-Vacancy (NV) centers in diamond. Techniques include shallow single NV sensors; wide-field (greater than 1 mm) imaging using dense NV surface layers; Fourier (k-space) imaging using pulsed magnetic field gradients and compressed sensing speed-up; Berry phase magnetometry; and spin-to-charge-state readout. Applications include nanoscale NMR and MRI down to single molecules and spins; studies of both static and dynamic magnetic signals from a wide variety of biological phenomena; and probing of magnetic materials relevant to Earth and planetary science and condensed matter physics.

Stanford University APPLIED PHYSICS/PHYSICS COLLOQUIUM Tuesday, April 2, 2019 4:30 p.m. on campus in Hewlett Teaching Center, Rm. 201 Ronald Walsworth Harvard University and Smithsonian Institution “Quantum Diamond Sensors” In recent years, optically probed nitrogen–vacancy (NV) quantum defects in diamond have become a leading modality for magnetic, electrical, and temperature sensing at short length scales (nanometers to millimeters) under ambient conditions. This technology has wide-ranging application across the physical and life sciences — from NMR spectroscopy at the scale of individual cells to improved biomedical diagnostics to the search for dark matter. I will provide an overview of quantum diamond sensors and their diverse applications.

Recorded from IQC's NanoMRI conference 2015. The nitrogen vacancy (NV) centre in diamond is an atom-sized defect in diamond that is a remarkably good sensor of magnetic, electric, thermal, and strain fields on the nanoscale. In this talk, I describe the development of an NV-based scanning probe magnetometer and its application to studying nanoscale magnetism in condensed matter systems. Importantly the magnetometer operates at liquid helium temperatures, opening up the possibility of exploring various condensed matter phenomena at low temperatures. Magnetic images indicate our scanning magnometer has nanometer-scale stability and spatial resolution. I also present measurements of high-quality diamond mechanical resonators strain-coupled to embedded NV centres. Through strain coupling, we show that coherent echanical control of individual spins in diamond is possible. These results are encouraging for proposals to use such a spin-mechanical platform for spin-squeezing, phonon-meditated spin-spin interactions, and phonon cooling and lasing.

Stanford University APPLIED PHYSICS/PHYSICS COLLOQUIUM Tuesday, October 8, 2019 4:30 p.m. on campus in Hewlett Teaching Center, Rm. 200 Ania Bleszynski Jayich Dept. of Physics, University of Calif. at Santa Barbara “Quantum Sensing and Imaging with Diamond Spins” Quantum sensors based on optically addressable solid-state spins are powerful tools that offer high sensitivity, nanoscale spatial resolution, and quantitative field information. The nitrogen vacancy (NV) center in diamond is the most advanced such sensor because of its robust, room-temperature coherence and its high sensitivity to a variety of fields: magnetic, electric, thermal, and strain. Here I discuss an NV-based imaging platform where we have incorporated an NV center into a scanning probe microscope and used it to image skyrmions, nanoscale topological spin textures. I also discuss recent experiments that utilize the NV center’s sensitivity to fluctuating magnetic fields to image conductivity with nanoscale spatial resolution. A grand challenge to improving the spatial resolution and magnetic sensitivity of the NV is mitigating surface-induced quantum decoherence, which I will discuss in the second part of this talk. Decoherence at interfaces is a universal problem that affects many quantum technologies, but the microscopic origins are as yet unclear. Our studies guide the ongoing development of quantum control and materials control, pushing towards the ultimate goal of NV-based single nuclear spin imaging.

June 18, 2021 GSSA Lunchtime Talk with Dr Karen Smit Preservation of Archaean Mantle Below the Grib Kimberlite Pipe (NW Russia

25 June Overberg Geoscientists Group talk by Dr John Bristow

30 July 2020 Overberg Geoscientists Group talk with Jim Davidson Secrets of Fissure Diamond Mining

Seminar on March 30, 2021 at 6 PM (PST) hosted by Katherine Landoni and convened by Barbara Scott Smith. Sponsored by SRK Consulting (https://cdn-web-content.srk.com/uploa...​). Braúna 3 Mine - South America’s First Diamond Mine Developed On A Kimberlite Deposit presented by Mr. Kenneth Johnson and Dr. José Paulo Donatti-Filho (both from Lipari Mineração Ltda.) Find the full abstract on the VKC website. Hosted by: Katherine Landoni

15 October 2020 Overberg Geoscientists Group talk by Bill McKechnie

Nicole Meyer (University of Alberta, PhD candidate) presents: "Diamonds and Their Inclusions From The Koffiefontein Pipe Provide Insights Into the Formation and Evolution of the Kaapvaal Craton" Seminar was live on Feb 24, 2021 at 6 PM (PST) hosted by Katherine Landoni and convened by Barbara Scott Smith. Sponsored by SRK Consulting (https://cdn-web-content.srk.com/upload/user/image/SRK%20Diamond%20Group_2020_Spreads20201117125325026.pdf?_ga=2.196734636.1489000300.1613172515-924229164.1553535947). Seminar Abstract: Diamonds and their mineral inclusions preserve mantle processes over space and time. Forming over a protracted period, diamonds also provide snapshots of early craton formation and mantle evolution over much of Earth’s history. The lithosphere beneath Koffiefontein is extremely depleted and is characterised by high-Mg# olivine and low-Ca garnet. In addition to garnet LREE enrichment, Koffiefontein experienced a unique K-Nb-Ta-rich metasomatism event that resulted in new minerals. The lack of clinopyroxene and co-existing garnet-orthopyroxene assemblages lead to the use of the electron microprobe for trace element analysis of Al in olivine. Geothermobarometry indicates that upper mantle diamond formation conditions are 1100-1300 °C and 4-7 GPa. Koffiefontein diamonds have a main δ13C mode for both peridotitic and eclogitic diamonds similar to mantle carbon. Relationships of δ15N-[N] and δ13C-δ15N indicate that nitrogen was derived from subducted sources and suggests that formation of not only eclogitic but also peridotitic diamonds involved fluids derived from altered oceanic crust. Lower mantle diamonds with coexisting ferropericlase and former bridgmanite indicate formation at or below 660 km. The high bulk Mg# of this assemblage is consistent with the diamond substrate originating from the depleted lithospheric mantle portion of an oceanic slab. Diamond formation at Koffiefontein dominantly takes place in depleted peridotite at both lithospheric and lower mantle depths. The δ13C-δ15N systematics suggest the same subducted source for both peridotitic and eclogitic diamonds. Subduction has played an important role in the formation and evolution of the Kaapvaal Craton and subsequent diamond formation.

Red Cloud Financial Services Presents the Pre-PDAC Mining Showcase George Read, Senior Technical Advisor, Star Diamond Corp. presents a company update. Edited by Red Cloud Media.

Telling the story of natural diamonds, along with tracking them through the rough-to-polished process