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Helenite, also known as Mount St. Helens obsidian, emerald obsidianite, and ruby obsidianite, is a glass made from the fused volcanic rock dust from Mount St. Helens and marketed as a gemstone. [1] [2] Helenite was first created accidentally after the eruption of Mount St. Helens in 1980.
Obsidian (/ ə b ˈ s ɪ d i. ən, ɒ b-/ əb-SID-ee-ən ob-) [5] is a naturally occurring volcanic glass formed when lava extruded from a volcano cools rapidly with minimal crystal growth. It is an igneous rock. [6] Produced from felsic lava, obsidian is rich in the lighter elements such as silicon, oxygen, aluminium, sodium, and potassium.
Cumberlandite is a specific type of plutonic rock called a melanocratic troctolite, or melatroctolite. [1] It is the state rock of Rhode Island and can be found in a 4-acre (0.016 km 2) lot in Cumberland, Rhode Island at Iron Mine Hill. [2] [3] Further traces can be found scattered throughout the Narragansett Bay watershed as far as Martha's ...
Fulgurites are formed when lightning strikes the ground, fusing and vitrifying mineral grains. [7] The primary SiO 2 phase in common tube fulgurites is lechatelierite , an amorphous silica glass. Many fulgurites show some evidence of crystallization: in addition to glasses, many are partially protocrystalline or microcrystalline .
Impactite is rock created or modified by one or more impacts of a meteorite. [1] [2] Impactites are considered metamorphic rock, because their source materials were modified by the heat and pressure of the impact. [3] On Earth, impactites consist primarily of modified terrestrial material, sometimes with pieces of the original meteorite. [3]
Xenonite, created by the alien Eridians, is a metal with varying types. Made primarily of the noble gas xenon, it can be used for building, engineering, and much more. It has virtually unlimited tensile strength; a wide variety of colors, including transparent and tan; and even different textures.
Well-formed crystals typically form as a druse (a layer of crystals lining a void), of which quartz geodes are particularly fine examples. [24] The crystals are attached at one end to the enclosing rock, and only one termination pyramid is present.
The proportion of silica in rocks and minerals is a major factor in determining their names and properties. [7] Rock outcrop along a mountain creek near Orosí, Costa Rica. Rocks are classified according to characteristics such as mineral and chemical composition, permeability, texture of the constituent particles, and particle size. These ...