colour variations on ivory

[asomotif]

There are african horns made from ivory.
They come from the Benin / Cote ivore region.
and they vary between white and red. maybe natural, or maybe coloured I don't know.

I have heard that in africa ivory object are sometimes rubbed with material to colour it. But I also have seen an ivory bracelet where the ivory itself had parts that where red of colour and this was the natural colour.

But indeed I also see items now and then that are artificially aged sometimes by burning it over a flame.

Ps. I also have seen african lip plugs that had extensive crackings and the seller was honest enough to tell that this was done artifically.
They heat up the ivory and then cool it down very fast in water causing the material to crack.
We bought the lip plug never the less, and after a few months pieces of ivory started to fall off.
So this artificial cracking is very bad for the firm structure of the material.

Ps. marine ivory from the sperm whale has dark parts.
You see bugis hilts occasinally made of sperm whale. see this example.