Benitoite mohs score

[Slykat12]

Hi. i am totally wanting a benitoite and want to make it into a pendant. I have learned it is a soft stone with a mohs of about 6-6.5 and am curious about this.
I mean how soft is that?
Could my fingernail dent it?
Will it be hard to set in a pendant or be damaged in the process?
thanky

 

[valeria101]

Date: 12/30/2005 4:56:13 PM
Author:Kimberly

Hi. i am totally wanting a benitoite and want to make it into a pendant. I have learned it is a soft stone with a mohs of about 6-6.5 and am curious about this.
I mean how soft is that?

Like Tanzanite - a stone very often used, as you know.



Could my fingernail dent it?

No, no way. No gem can be damaged with a finger - not even the softest ever used (opal, apatite).


Will it be hard to set in a pendant or be damaged in the process?

It can't be that bad.

For fun... since these questions are often asked, someone came up with the Mohs scores of references things. You may find this useful:

On the Mohs scale:

- fingernail has hardness 2;
- copper penny about 3;
- a knife blade 5;
- window glass 5.5;
- steel file 6.5.

Well, I wouldn't try to scratch glass with it! The Mohs scale does not catch resistance to blows (chipping) and exactly what king of abuse a piece can handle depends on the share too. Anyway, in theory, it should work according to those ratings.


The low-down on Benitoite phisical properties is cited HERE among others.

Citing the source:

Benitote...

Hardness: 6-6.5. (I wish they used a cardinal scale!)
Cleavage: {1011}, imperfect. (good thing, this means it isn't particularly senzitive to shocks from any particular direction)Toughness: Fair; brittle. (it doesn't have particularly bad reputation for cutting - so, it can't be too bad.).
Refractive indices: o = 1.756-1.759; e = 1.802-1.804. Uniaxial (+). (close to sapphire)
Dispersion: 0.046. (low - not fiery, close to sapphire again)
Fluorescence: Intense bluish white under SW (254 nm). Occ. dull red under LW (365 nm). (not all, as far as I know)
Stability: Sensitive to rapid temperature changes and ultrasonic vibration. (the heat senzitivity is more about jeweler's work
and cuting when high temperature is involved. It
can't hurt to keep it out of the steam and
ultrasonic cleaners, perhaps... )

PS. sorry for the laundry list - just wanted to leave some refference on the forum. There isn't much about Benitoite around.

 

[colormyworld]

Hi Kimberly, While I am no expert. With a little thought to ensure the gridle is protected I think benitoite would work well in a pendant. As far as setting a stone with a 6 to 6.5 hardness I would check around with various jewelers to see if the are used to working with softer stones. I made the mistake of letting a jeweler who was used to sapphires ruby and diamonds set a spinel ( 8 on the mohs scale) and they scratched it. Hope this helps. Happy New Years. doug

 

[Slykat12]

thankyou so much. We are driving to Clovis Cali to pick one out and I got my eye on a nice pear. Just wanted to be sure it would not be harmed as colored gems are new to me.

 

[Slykat12]

Thanky so much. I am driving to Clovis Cali to get one soon!!!!

 

[MJO]

The best place for Benitoite is:

WWW.wsfgems.com

W.S.F. Gemstones
438 Clovis Ave.
Clovis, CA 93612
ph/fax (559) 298-6584

Scott's father owned the mine for years.

Regards,
Maurice