SG : 3.33
Methylene Iodide is the most useful specific gravity liquid to the
gemmologist. It possess a higher density than most of other pure
liquids, but also do have a high refractive index, RI : 1.74 which
gives its great value.
Methylene iodide diluted with Monobromonaphtalene to an SG of 3.05
will distinguished between :
- Tourmaline, SG : 3.05, the tourmaline will suspend.
- Nephrite Jade, SG : 3.00, nephrite will float.
- Jadeite, SG : 3.34, jadeite will sink (very slowly).
Methylene iodide is very usefull for ‘immersion method’.