• Home
  • Health
    • Anatomy and Physiology
    • Common Ailments
    • Complementary Medicine
    • Foods
    • For Seniors
    • Herbs
    • Microbes
    • Nutrients
    • Nutrition
    • Therapeutic Essential Oils
  • Science
    • Ancient Astronomy
    • Botany
    • Chemistry
    • Earth Sciences
    • Ecology
    • Mathematics
    • Zoology
  • Society
    • Business
    • Education
    • Government
  • Culture
    • Arts
    • Literature
    • Religion
    • Travel
  • Our Books
  • Contact Us


Home › Science › Earth Sciences › Geology › Glossary

Glossary

Amorphous:
Not having crystalline properties, as glass, amber, and opal.
Anatectic:
Having melted from preexistent rock.
Asterism:
A star effect by some gems when viewed under strong light.
Carat:
A unit of weight (one-fifth of a gram by which gemstones are weighed.
Chatoyant:
An optical phenomenon resembling the narrow pupil of a cat’s eye seen when a stone is tilted under a strong light.
Clasts:
Fragments of rocks or minerals resulting from the mechanical breakdown of another rock.
Contact rocks:
Rocks in contact with, or near, an igneous intrusion that have been metamorphosed by the heat of the intrusion.
Cubic:
The shape of a gaming die.
Dichroic:
Showing two colours when viewed through a dicroscope.
Dike:
A vertical to sub-vertical intrusive sheet.
Evaporite:
Sedimentary rock or mineral that precipitates from solutions through evaporation.
Extrusive:
Pertaining to igneous rocks that solidify on the surface of the earth.
Facet:
A polished, flat plane on the surface of a cut gem.
Fluorescent:
Appearing to have one colour when viewed in normal light and to glow a different colour when viewed under ultraviolet light.
Gemstone:
Any naturally occurring material that happens to be regarded as valuable.
Hexagonal:
The shape of having a symmetry of a six-fold vertical axis.
Hypabyssal:
Pertaining to a shallow intrusion.
Igneous Rock:
A rock formed from molten material, magma if underground, or lava if erupted onto the surface.
Intrusive:
Pertaining to igneous rocks that solidify beneath the surface of the earth.
Metamorphic Rock:
A rock altered by heat and/or pressure.
Metasomatic:
Having changed because of addition or loss of chemical components.
Mineral:
A material in which all specimens have the same chemical formaula and crystal symmetry.
Mohs’ Scale of Hardness:
Based on the ease of scratching one of its surfaces with the sharp edge of a mineral of known hardness.

  1. talc
  2. gypsum
  3. calcite
  4. fluorite
  5. apatite
  6. orthoclase
  7. quartz
  8. topaz
  9. corundum
  10. diamond
Monoclinic:
The shape in which no pair of crystals has the same length, width, or height as any other, and having a two-fold axis.
Opalescent:
Showing a display of colours across the surfaces.
Opaque:
Through which light cannot travel.
Orthorhombic:
The shape having three faces that are unequal in length, width, and height, but at right angles to each other.
Pleochroism:
An optical phenomenon whereby a stone appears to change colours when viewed from different angles and in different lights.
Porphyritic:
Consisting of feldspar crystals embedded in a compact fine-grained base material.
Regional Metamorphism:
Metamorphism that affects vast areas of the earth’s crust.
Rock:
A combination of several different minerals, although occasionally only one.
Sedimentary Rock:
A rock formed by the accumulation and consolidation of layers of loose sediment, or by the accumulation of chemicals that precipitate out of water.
Tetragonal:
The shape of a box that has had its top and bottom removed, an open shape which needs to combine with other shapes to make a complete crystal.
Translucent:
Transmitting light imperfectly so that one cannot see through a material clearly.
Triclinic:
The shape of having no face with the same dimensions and not at right angles to any others.
Trigonal:
The shape with three equal axes, equally inclined, but not at right angles to each other.
Variety:
Different types and colours of a gem within a species.








Search


Follow Us

Innvista

Google Translate

Nature’s Pharmacy





Copyright 2020 | All rights reserved | Innvista.com