What is the Gemstone that has this inclusion?

Question

Only one gemstone has a "horse hair" inclusion, which adds greatly to the value of this otherwise semi-precious gem. If you can name this stone species and color I will give you 5 stars. If you can only name the gem , I will give you 4. As a hint, this stone is found in all colors including black and is not a diamond.

Bear in mind that best answers cannot be given until the expiration of 4 hours according to message board rules. If you have answered correctly, I cannot give best answer until that time has expired.

Answer 1

How about a green Demantoid. (A Demantoid is the green gemstone variety of the mineral andradite, a member of the garnet group of minerals) Russian demantoid nearly always contains inclusions of byssolite, a variety of the mineral actinolite. These inclusions are feathery golden threads that tend to curve and resemble the tail of a horse, and are therefore referred to as horsetail inclusions.

Answer 2

Demantoid Garnet is found in the Andradite Garnet group. These Garnets contain titanium and maganese and the most valuable is demantoid, whose emerald green color is due to the presence of chromium. It has a higher dispersion than diamond and can be recognized by the characteristic 'horsetail' inclusion that is caused by traces of asbestos.

The horsehair inclusions are needlelike and look like this:

http://palagems.com/Images/demantoid/horsetails.jpg

Answer 3

Sadfire

Answer 4

Blood concrete, which is actually more brown than red. The horsehair protects against shrinkage over time, and the blood protects against frost damage.

Answer 5

Ruby spinel?

Answer 6

demantoid garnet, so green?

Answer 7

I am game...?spinel?