magnesium phosphate Color?

[YT2095]

Could my trusty old data-book have yet Another error in it?

 

it clearly states that Mg3(PO4)2.4H2O is a Blue monoclinic crystal, since I like "collecting" colored crystals I put a chunk of Mg into some Phoshoric acid to make some.

It`s Not blue.

in fact if anything it`s a clear to grey liquid without even the slightest hint of blue with a white paper test.

I`ve tried to google for it, and there`s no mention of blue there either, anyone have any ideas what it could be on about? or is it just another error (like the MP of NaHSO4 being 6588 kelvin!).

[woelen]

No, if pure, it is white. In practice it may be very light grey. Just as with calcium phosphate.

 

Magnesium salts usually are white or off-white, simply because the Mg(2+) ion is colorless. If color is imparted to magnesium salts then the anion gives the color to the salt.

[5614]

Mg3(PO4)2.5H2O is a white powder

 

sources:

http://composite.about.com/library/glossary/m/bldef-m3191.htm

http://www.jostchemical.com/chemicals/2565.html

http://physchem.ox.ac.uk/MSDS/MA/magnesium_phosphate_dibasic_trihydrate.html

 

Hydrated magnesium phosphate carbonate hydroxide is blue, which is possibly where the book went wrong, maybe.

 

[edit] woelen's post wasn't there 2mins ago when I loaded the page.

[YT2095]

well I thought it was strange myself (that`s why I tried it), all the Mg salts I`ve encountered are as you say, either white or clear.

 

I`ll chalk it up to yet Another error in this book

 

the 1`st one I ever noticed in it was the BP of H2O2 being 323 kelvin, Grrr...

 

Thanx Both