Emerald

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Emerald
Emerald crystal muzo colombia.jpg
Emerald crystal from Muzo, Colombia
General
Category Beryl variety
Formula
(repeating unit)
Be3Al2(SiO3)6
Crystal symmetry (6/m 2/m 2/m) – Dihexagonal Dipyramidal
Unit cell a = 9.21 Å, c = 9.19 Å; Z = 2
Identification
Formula mass 537.50
Color Green shades
Crystal habit Massive to well Crystalline
Crystal system Hexagonal (6/m 2/m 2/m) Space group: P6/mсc
Cleavage Imperfect on the [0001]
Fracture Conchoidal
Mohs scale hardness 7.5–8
Luster Vitreous
Streak White
Diaphaneity Transparent to opaque
Specific gravity Average 2.76
Optical properties Uniaxial (-)
Refractive index nω = 1.564–1.595,
nε = 1.568–1.602
Birefringence δ = 0.0040–0.0070
Ultraviolet fluorescence None (some fracture filling materials used to improve emerald's clarity do fluoresce, but the stone itself does not)
References [1]

An emerald is a mineral rock and a variety of beryl. It is the birthstone of someone whose birthday is in the month of May. It is a green rock. The emerald is one of the most valuable gems, along with the ruby, the opal, topaz, the diamond, and a sapphire.

Etymology[change | change source]

The word emerald comes from Vulgar Latin. The word was Esmaralda/Esmaraldus, a different way of saying the Latin word Smaragdus, which came from the Greek, σμάραγδος (smaragdos; "green gem").[2][3] It first came from a Semitic word, izmargad (אזמרגד). This meant "emerald" or "green".[2] The name could also be related to the Semitic word baraq (בָּרָק ;البُراق; "lightning" or "shine") (c.f. Hebrew: ברקת bareqeth and Arabic: برق, barq, "lightning"). It is where the Persian (زمرّد zomorrod), Turkish (zümrüt), Sanskrit (मरग्दम् maragdam) and Russian (изумруд; izumrúd) words came from.[3]

Related pages[change | change source]

References[change | change source]

  1. "Emerald at Mindat". Mindat.org. 2010-07-19. http://www.mindat.org/min-1375.html. Retrieved 2010-07-30.
  2. 2.0 2.1 Fernie M.D., W.T. (1906). Precious Stones for Curative Wear. John Wright. & Co..
  3. 3.0 3.1 "Online Etymology Dictionary". etymonline.com. http://www.etymonline.com/index.php?search=emerald&searchmode=none. Retrieved 15 April 2010.