The PGs Dictionary

THE PLANETARY GEMOLOGISTS DICTIONARY

  • ADULARESCENCE: An optical phenomenon applied to orthoclase or adulria feldspar that exhibits a floating, billowy, white or bluish light effect.
  • AGGREGATE: Crystalline aggregate made up of many particles, each of an individual crystal too small to be seen by the unaided eye.
  • ANTAR-DASHA: Minor planetary period.
  • ANUKUL: Favorable (Anukula-vad is belief that jyotish gems act same as their ruling planet, therefore gems should only be used for anukul or favourable planetary positions)
  • BIREFRINGENCE: The strength of double refraction measured by taking the difference between the high and low refractive indices of a doubly refractive gemstone.
  • CHANDRA-RASI: Moon sign.
  • CRYSTAL SYSTEM: One of the six groups of crystal patterns in which minerals and other crystalline solids occur. They are : cubic, tetragonal, hexagonal, orthorhombic, monoclinic and triclinic.
  • CUBIC: Highly symmetrical crystal system with three equal crystallographic axes at right angles.
  • DICHROISM: The property of doubly refractive colored gemstones of transmitting two different colors in two different directions caused by their unequal absorption of the two portions of a doubly refracted beam of light.
  • DISPERSION: The property of a transparent gemstone to separate white light into its component colors.
  • DOUBLE REFRACTION: The property of separating a single ray of light into two.
  • FLUORESCENCE: The emission of visible light by a gem when exposed to ultra-violet or X-radiation.
  • GAURA-PAKSHA: The bright fortnight.
  • HEXAGONAL: A crystal system having three equal axes at 60 degrees and a fourth axes perpendicular to the other three and unequal in length.
  • INCLUSION: Any internal foreign body or imperfection in a gem.
  • JANMA-PATRIKA: Sidereal horoscope.
  • JYOTISH: Vedic sidereal astrology.
  • JYOTISH-ACARYA: A master-teacher of Vedic sidereal astrology.
  • KAVACHA: A shield, amulet or talisman.
  • KETU: The Moon’s descending (South) node.
  • KRISHNA-PAKSHA: The dark fortnight.
  • KRURA-GRAHA: A harmful planet.
  • LAGNA: Rising sign.
  • MAHA-DASHA: Major planetary period.
  • MANI: Gem or jewel.
  • MANTRA: A combination of transcendental (Sanskrit) sound vibrations with the power to deliver the mind from material limitations.
  • MATRIX: The rock in which a mineral is contained.
  • MOHS SCALE: The most commonly used scale of relative hardness of minerals with numbers from one to ten assigned to ten minerals of increasing hardness from talc to diamond.
  • MONOCLINIC: A crystal system with two axes unequal in length at right angles to one another and a third axes of unequal length which is not at right angles to the plane of the other two.
  • NACRE: Pearl substance.
  • NAKSATRA: Moon constellation (There are 27 constellations).
  • NAVA-RATNA: The Nine Gems.
  • OPTIC CHARACTER: The nature of a gem as either uniaxial (singly refractive) or biaxial (doubly refractive).
  • ORIENT: The iridescent luster of a pearl.
  • ORTHORHOMBIC: A crystal system with three axes of unequal length, each perpendicular to the plane of the other two axes.
  • PANCHA-RATNA: The Five Gems.
  • PLEOCHROISM: The property of most doubly refractive colored gemstones of exhibiting either two or more different colors when observed through a dichroscope in transmitted light.
  • PRATIKUL: Unfavorable (Pratikula-vad is belief that jyotish gems act OPPOSITE of ttheir ruling planet, therefore gems should only be used for pratikul or unfavourable planetary positions)
  • RAHU: The Moon’s ascending (North) node.
  • RASI: Zodiac sign.
  • RATNA: Gem or jewel.
  • REFRACTIVE INDEX: A measure of the amount a light ray is bent as it enters or leaves a gemstone.
  • SAPTA-RATNA: The Seven Gems.
  • SHUKLA-PAKSHA: The bright fortnight.
  • SUBHA-GRAHA: A helpful planet.
  • SIDEREAL: Constellational astrology.
  • SINGLE REFRACTION: When a light ray enters either an isometric or amorphous gem substance, it remains intact and is refracted in the normal manner as a singly ray.
  • SPECIFIC GRAVITY: The ratio of the weight of a gemstone to that of an equal volume of water at 4 degrees centigrade.
  • STOTRAM: A Sanskrit prayer and invocation.
  • TETRAGONAL: A crystal system with two axes equal in length and at right angles with a third axes at right angles to the first two.
  • TRICHROISM: The property of most doubly refractive, colored gemstones belonging to the orthorhombic, monoclinic, and triclinic crystal systems, of transmitting three different colors in three different directions when observed through a dichroscope in transmitted light.
  • TRICLINIC: The least symmetrical crystal system with three axes, no two of which are of equal length and no two of which are perpendicular to one another.
  • TRI-RATNA: The Three Gems.

Ref. ©1995 Ancient Astrological Gemstones & Talismans

The Sanskrit name for the PGA was composed by HONORARY PATRON Prof. Dr. Satya Vrat Shastri, Padma Sri

TOP