Browsing by Subject "Crystals"
Now showing items 1-14 of 14
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Chemical Diffusion in Watermelon Tourmaline : Parallel Versus Perpendicular to C-axis
(2018-02-09)The chemical composition of tourmaline can provide unique insights into the thermal evolution of their growth environment, including that of pegmatites (in igneous systems) and hydrothermal veins (in metamorphic systems). ... -
Color in Watermelon Tourmaline : The Role of Hydroxyl Diffusion
(2018-05)Tourmaline is a semiprecious gemstone known in the geologic community known for its complex chemical formula. This is because the crystal structure of tourmaline can incorporate and contain numerous elements from the ... -
Color Variation in Gemmy Amethyst : The Role of Contaminant Diffusion
(2018-04)The role of contaminant diffusion purple quartz, otherwise known as amethyst, is commonly known for its occurrence as clusters of gemmy crystals that grow on the walls of fluid-filled fractures and vugs in hydrothermal ... -
Crystal diving for fluid inclusions
(St. Croix Rockhounds, Stillwater, MN, 1989) -
The Distribution of Hydrous Impurities in Quartz : The Role of Twinning
(2018-04)Quartz crystals have been studied since ancient times by scientists and natural philosophers attempting to unlock the mysteries behind their aesthetic appearance and cryptic morphological properties. Previous studies ... -
How fast can crystals grow?
(St. Croix Rockhounds, Stillwater, MN, 2004) -
Metal Sequestration During Aggregation Based Crystal Growth
(2018-01-09)This project is focused on determining how associated metals of environmental concern (especially Pb) behave during aggregationbased crystal growth as a function of increasing Crystallinity Index (CI). -
Minnesota twin crystals
(St. Croix Rockhounds, Stillwater, MN, 1989) -
Simulating Crystal Growth with Contaminant Diffusion : Computational Analysis in MATLAB
(2019-05)Radiometric dating is one of the most popular methods of exploring the history of Earth, but not all environments have reliable radioactive isotopes. Diffusion profiles of crystals contain information on the state of the ... -
Water in Hydrothermal Feldspar
(2015-04)Feldspar is the most common mineral in the Earth's crust, and although water is present in only trace amounts (~ hundreds of ppm), this quantity is sufficient to make crustal feldspar one of, if not the, largest reservoir ... -
What's in a vug?
(St. Croix Rockhounds, Stillwater, MN, 1988) -
Why do such large crystals form in pegmatites?
(St. Croix Rockhounds, Stillwater, MN, 1987) -
Why pyrite crystals have different shapes
(St. Croix Rockhounds, Stillwater, MN, 1994) -
The world's largest crystal
(St. Croix Rockhounds, Stillwater, MN, 1988)