Blue John
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Physical & Optical Properties
Category
Semi-Precious Gems
Mohs Hardness
4.0
Specific Gravity
3.0 – 3.25
Refractive Index
1.432 – 1.436
Crystal System
Isometric
Luster
Vitreous
Cleavage
Perfect
Color
various
Mohs Hardness
Mohs Hardness: 4.0
1 Soft10 Hard
Crystal System
Value & Market
Price Tier
Budget (< $50/ct)
Where to Buy Blue John
Blue Nile
Fine jewelry retailer
James Allen
Gemstone jewelry
Brilliant Earth
Ethically sourced gems
Amazon
Wide selection
Links may earn a commission at no extra cost to you.
Treatments
4Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
3.00 to 3.25Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
PerfectHerve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
1.432 to 1.436Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
IsotropicUlrich Henn and Claudio C. Milisenda, Gemmological Tables (2004)
Banded white/purpleGemdat.org, Management Team (2012)
Transparent,TranslucentArthur Thomas, Gemstones (2009)
VitreousArthur Thomas, Gemstones (2009)
IsometricHerve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
Cubic, massiveArthur Thomas, Gemstones (2009)
Blue John information at mindat.org
UK
[www.thamesvalleyminerals.com]
Fluorite: The Collector's Choice. Extra Lapis English No. 9
About Blue John
블루존은 영국 더비셔 주 캐슬턴 지역에서만 산출되는 희귀한 자주색-황색 줄무늬 형석(플루오라이트)으로, 세계 유일의 산지를 자랑합니다. 특유의 동심원형 자주색 줄무늬가 아름다우며, '블루존'이라는 이름은 프랑스어 '블루-자운(bleu-jaune, 청-황색)'에서 유래했다고 전해집니다. 장식품과 조각품에 사용되며, 영국의 국가 유산으로도 보호받고 있습니다.
Jewelry Use
Durability
3/10
Science FYI Family
Frequently Asked Questions
What is Blue John?
블루존은 영국 더비셔 주 캐슬턴 지역에서만 산출되는 희귀한 자주색-황색 줄무늬 형석(플루오라이트)으로, 세계 유일의 산지를 자랑합니다. 특유의 동심원형 자주색 줄무늬가 아름다우며, '블루존'이라는 이름은 프랑스어 '블루-자운(bleu-jaune, 청-황색)'에서 유래했다고 전해집니다. 장식품과 조각품에 사용되며, 영국의 국가 유산으로도 보호받고 있습니다.
What is the hardness of Blue John?
Blue John has a Mohs hardness of 4.0, making it relatively soft for use in jewelry.
What color is Blue John?
Blue John is primarily Various.
How much does Blue John cost?
Blue John falls into the Budget (< $50/ct) price range. Prices vary based on color, clarity, cut, and origin.
What is the crystal system of Blue John?
Blue John belongs to the Isometric crystal system.