MBCH198306

$11.00

Blue Chalcedony 3mm x 6mm x 16β€³ (MBCH198306). Hole 0.8 mm, approximately 127 beads.

In stock

SKU: MBCH198306
Category: ,

Description

Blue Chalcedony

  • ChalcedonyΒ is microcrystalline or cryptocrystalline quartz; hexagonal (trigonal) crystal system; chemical composition SiO2
  • semitransparent

Identification

  • Optic Character: AGG
  • Refractive Index: 1.535-1.539; 1.53 or 1.54 spot reading
  • Birefringence: usually not detectable, but may show .004
  • Pleochroism: noneΒ 
  • Ultraviolet Fluorescence: generally inert (LW and SW); some may fluoresce a yellowish green (LW and SW)
  • Absorption Spectra: dyed green – vague lines around 645 and 670 nm
  • Specific Gravity: 2.60 (+.10,-.05)
  • Polish Luster: greasy to vitreous
  • Fracture: conchoidal; sometimes granular
  • Luster: dull to waxy
  • Cleavage: none
  • Identifying Characteristics: dyed green and dyed blue appear red or pinkish through Chelsea filter
  • Crystal Habit: aggregate, often in botryoidal forms
  • Hardness: 6 Β½Β  to 7
  • Toughness: good

Enhancements

  • Method: dyeing

Effect: chalcedony is dyed to practically all colors for various uses; the bands in agate and Onyx accept dye differently so that a green dye, for example, may impart color to some layers and leave others white.
Prevalence: common
Detection: appearance (color often looks unnatural), spectrum, Chelsea filter reaction, SG (dyed green often lower (2.60 or less) than chrysoprase)
Stability: generally stable
Special Care Instructions: none

Birthstone Designation(s)

  • chalcedony – 8:00 pm

 

Stone information is reference from

Gem Reference Guide, Published by GIA. ISBN 0-87311-019-6

Gemstones of the World, Published by Sterling Publishing Co., Inc NY, ISBN 1-4027-4016-6

Encyclopedia of GEMSTONE, Published by ISHINSHA CO., LTD. ISBN 978-986-251-831-1

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