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Benitoite and Kornerupine: Help Me Understand the Appeal

Discussion in 'Colored Gemstones' started by voce, Feb 11, 2019 at 4:26 PM.

  1. voce
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    by voce » Feb 11, 2019 at 4:26 PM
    I know that benitoite and kornerupine are different minerals. They are both around 6-6.5 on the Mohs scale. They both can range from transparent to a saturated blue, and in the case of kornerupine, green. I know that these minerals are rare, benitoite rarer than kornerupine.

    The question I have is: why are these gemstones used in jewelry? They don't look (at least to me) to provide a unique tone of color, and neither is as dispersive or gorgeous as sphene, in my humble opinion. Yes, they are rare, but why wouldn't you want to have sapphire instead, which can match the color/crystal and be more durable?

    Perhaps I haven't seen the finest examples of kornerupine and benitoite? What makes people take a look at them and think they must have them set in jewelry instead of leaving them in a collector's little gem box? Please educate me!
     
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  2. lilmosun
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    by lilmosun » Feb 11, 2019 at 6:07 PM
    Kornerupine is one of my favorite sidestones..not the yellow/green/brown ones but the blue/green/violet ones . They can be dichroic/pleochroic so they can exhibit different colors when viewed at different angles,so I find them boyh interesting and pretty.
     
  3. lilmosun
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  4. voce
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    by voce » Feb 11, 2019 at 6:22 PM
    @lilmosun thanks for showing me these pictures of kornerupines. They certain look better than the yellow/green ones that I remembered. The pleochroism in these pictures feels a little unsettling to me, because whereas the pleochroism in sphene feels "wam", there is something that feels "eery and alien" to me about the color shift in these kornerupine examples.
     
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  5. leslie1956
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    by leslie1956 » Feb 11, 2019 at 7:16 PM
    It may just be a personal taste issue :) I love the shifting blues greens and violets of kornerupine, especially when set in rose gold. I would never buy sphene because yellows look awful on me. I stay away from chrysoberyl and yellow sapphires for the same reason :)
     
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  6. lovedogs
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    by lovedogs » Feb 11, 2019 at 8:03 PM
    I'm not a huge fan of benitoite, because it looks blue like sapphire, but is less hard. But it's definitely a collectors gem due to rarity. I do like kornerupine (especially the lovely ones from people like @lilmosun), but I've seen ones that I like a lot less (e.g. brown tones).
     
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  7. T L
    Super_Ideal_Rock

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    by T L » Feb 11, 2019 at 8:56 PM
    Benitoite reminds of a decent blue spinel, The uncut crystals in fine form are highly prized.
     
  8. pwsg07
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    by pwsg07 » Feb 12, 2019 at 2:55 PM
    Benitoite has a high R I. In real life I have never seen one that appeals to me.
     
  9. Nosean
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    by Nosean » Feb 12, 2019 at 3:53 PM
    https://www.instagram.com/benitoite...tm_source=ig_share_sheet&igshid=19ph3x2b6d80x

    Dispersion in combination with flashes of strong blue ( strong dichroism with a colorless to greengray = c-axis and cornflowerblue to dark violetblue).
    Ethical mined only in California from a small group of miner for more than 100 years. High quality in cutting. There are some rare colorless stones and heated peach to pink stones.

    My favorite collector gem.

    Kornerupine comes in many colors - boring colors from Sri Lanka and Madagascar but awesome chromium variety with strong pleochroism and a vanadium bearing vivid bluishgreen variety from Tanzania and Kenia. Sri Lanka produces razor sharp cat eyes...

    https://www.instagram.com/p/BlGBCbuHuW8/?utm_source=ig_share_sheet&igshid=1u5tnjo2e0w8t

    A vanadium kornerupine...
     
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  10. suzanne2
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    by suzanne2 » Feb 12, 2019 at 8:05 PM
    I was at a gem show discussing benitoite with a vendor last year. He pulled out boxes and boxes of the stones, each showing from bright to pale, about 7 to 8 stones each. Just like this.

    [​IMG]

    I was intrigued, but not stunned. They might be collectors stones but didn't seem to be that special.
     
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  11. leslie1956
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    by leslie1956 » Feb 12, 2019 at 8:16 PM
    That's kind of my reaction to benitoite, too, Suzanne. Other than its rarity, I don't see what the big fuss is about. If I want something that shade of blue, I'd just as soon get a sapphire!
     
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