Specification :

Additional information Idocrase in determining the pricing structure and color.
by Ricky Chang on January 16, 2012 at 22: 38

http: / / www.gemval.com/ chart.php? type= 54
Idocrase

Color: green, yellow, brown, orange, purple, red, blue, black, grey, white porcelain, and mix colours.
Hardness: 6.5- 7.2
Refractive index: 1.67 - 1.76
Density: 3.32 - 3.50
Chemical composition: Ca10( Mg, Fe) 2Al4( SiO4) 5( Si2O7) 2( OH) 4
Crystal structure: tetragonal
Origins: Canada, USA, Italy, Russia, Switzerland, Tanzania, Kenya, Sri Lanka, Indonesia.

Alternative name is vesuvianite. Rarely used in jewelry, the mineral is mostly interesting for collectors. Clean crystals over 5 ct. are rare. Unusual purple or blue varieties are the most expensive. Stones are generally not treated.

USA Standart Price Calculation method of Idocrase.

a) . For class A is :

Price for Idocrase class A in US $

( 65.92+ 14.87( n-1) ) k

k= 1.5, 2, 0.67, 0.5, 1.

note :

n= number of carat and k depend if AA then k= 1.5 or AAA then k= 2 as you told me yesterday

The price in that web I see is 65.82$

plus another 14.87$ for each carat added

if class B I will divide by 1.5 and if C by 2

b) . For class B is :

B class method : ( 44.81+ 10.78( n-1) ) k

c) . For class C is :

C class method is : ( 28.16+ 13.55( n-1) ) k

d) . For very rare class is :

D very rare class method is :

And for the very rare pink then would be

( 430.20+ 103.52( n-1) ) k
Gemstone Prices: Idocrase value charts
www.gemval.com
Online guide to gemstone prices for industry professionals; Idocrase value charts