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How Corals Feed: Symbiosis, Nutrition and Survival Under Stress

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A coral skeleton records growth, but living tissue supplies the energy that makes growth possible. Corals are animals, yet many reef corals obtain energy through a partnership with photosynthetic microorganisms. They can also feed on external resources. Understanding these energy pathways helps explain why changes in light, food and water conditions can affect coral growth and survival. [1] Two important energy pathways In photosymbiotic corals, algal partners capture light energy and share products of photosynthesis with the host. The animal also obtains food through heterotrophy, including the capture or uptake of organic resources. Their relative contributions differ among species and environments. [1] Symbiosis illustration, Figure 1 from the bleaching overview; used here to explain the nutritional partnership. Image: Norma Olguín-López and colleagues (2017) , IntechOpen source , CC BY 3.0 . Reproduced without scientific alteration. What does trophic plasticity mean? Trophic plasti...

Corundum gemological properties

Gemological Properties of Corundum S.No Description Physical properties / Optical properties 1 Chemical formula Al 2 O 3 2 Group Corundum 3 Crystal system Trigonal / Hexagonal 4 Color Colorless , Red, blue, green, orange, pink, yellow 5 Specific gravity 3.95 to 4 6 Hardness 9 7 Durability Excellent 8 R.I 1.762 to 1.770 9 Fluoresce Varies 10 Optical sign Uniaxial Negative 11 Inclusions Mostly, liquid inclusions, Needles, solid inclusions Further reading Corundum: History, Varieties, Properties, and Uses

Fluorite and its properties

  Gemological Properties of Fluorite S.No Description Fluorite Physical properties / Optical properties 1 Chemical formula CaF 2 2 Crystal system Cubic 3 Color Multi color , blue, green, colorless etc 4 Specific gravity 3.18 to 3.31 5 Hardness 4 6 Durability Poor 7 R.I 1.43 8 Fluoresce Inert to strong blue

Gemological properties of Afganite

  Afganite Properties S.No Description   Physical properties / Optical properties 1 Chemical formula (Na,Ca,K)8(Si,Al)12O24(SO4,Cl,CO3)3•(H2O) 2 Group Cancrinite 3 Crystal system Hexagonal 4 Color Mostly Blue 5 Specific gravity 2.56 to 2.85 6 Hardness 5.5 to 6 7 Durability Fair 8 R.I 1.522 to 1.533 9 Fluoresce Bright orange in long waves / inert in short waves 10 Optical sign Uniaxial negative 11 Inclusions May be speckled of dark blue inclusions of Lazurite Further reading Afghanite, The mineral afghanite information , pictures and stuff available for selling ib ebay store

Colored Gems Weight Estimation Tables

 Weight Estimation Tables for Colored Gems   To obtain approximate weights of the following shapes of colored stones multiply by the following measurements to millimeters. A listing of the specific gravities is below.   Round Faceted = ...................Diameter x diameter x depth x SG x .0018 Oval Faceted = .......................Diameter x diameter x depth x SG x .0020 Emerald Faceted = .................Length x width x depth x SG x .0025 Rectangle Faceted = .............Length x width x depth x SG x .0026 Square Faceted = ...................Length x width x depth x SG x .0025 Marquise Faceted = ...............Length x width x depth x SG x .0017 Pear Faceted = ........................Length x width x depth x SG x .0018 Heart Faceted = ...