Type IIb diamond is a rare species of diamond characterized by boron in the crystal structure that imparts an attractive blue color. The famous Hope Diamond is the perfect representation of this blue diamond. Type IIb diamonds have long been a mystery of geology, but new research published in the August 2, 2018 issue of Nature shows that they are “extra deep†diamonds, which means they are deeper than most other diamonds. Still deep. It is worth noting that the boron atoms contained in these blue diamonds may originally come from the ancient ocean.
Boron is an element that is concentrated on the surface of the earth. However, in the mantle where diamonds grow, the concentration of boron is extremely low. Therefore, the boron content of Type IIb diamonds is unexpected and difficult to interpret. Blue diamonds have been attracting the interest of scientists for decades, but the high value and rarity of these gemstones and their near-lack of mineral inclusions have been major obstacles to research.
Prior to this study, there was no knowledge of any mineral inclusions in Type IIb diamonds. However, after systematic screening of diamonds submitted to GIA in the last two years, we found and inspected 46 types of diamonds containing inclusions. The main rock and depth of diamond growth can be inferred by studying the inclusions. The formation of type IIb diamonds is at least as deep as the mantle transition zone (410-660 km) and reaches the lower mantle (>660 km). In contrast, this is 150–200km deeper than most other diamonds. It is about four times deeper.
The inclusions also indicate that at this large depth, the diamond is formed in the submerged belt of the conveyor belt and into the oceanic crust of the lower mantle. The connection to the subduction ocean lithosphere suggests that the boron responsible for the blue color of the Type IIb diamond may have been taken away from the Earth's surface.
When seawater seeps into the ocean floor, it causes a chemical reaction of boron, which deposits boron into the ocean lithosphere. The new study envisages a model in which some boron follows the water-bearing mineral subduction to the lower mantle. At this extremely deep depth, the increased temperature and pressure decompose the aqueous minerals and then release the boron-rich fluid, triggering the diamond to grow. A thin layer of methane and hydrogen coexisting on the surface of many solid inclusions in blue diamonds provides evidence that diamonds are formed in fluids rich in boron and water.
Plus Size Clothing,Cotton Knitted Dress,Plus Sizes Dress Office,Comfortable Breathable Sweater
SHAOXING LIDONG TRADING CO.,LTD , https://www.suejiangarments.com