Re: A question
Yttrium.
There has to be another mineral called Changesite that does not contain Yttrium...
I haven't been able to find the chemical formula ( which is strange, it has to be clearly defined for the IMA to accept a new mineral name ) but since there'es that trailing Y and it's a phosphate it at least contains the following elemen/complex : Y and PO4
now for a complete answer, I'm going to use a similar phosphate : merrillite and merrillite-Y
Merrillite : Ca8NaMg(PO4)7
Merrillite-Y : Ca16Y2Mg2(PO4)14
As you can see, the Yttrium replaced the Sodium in the formula...