Girls best friend ?

Clarity in crystal, a gift from natures purse,
amatory keepsake, which lovers eyes immerse.
A promise of betrothal, sculptured ring of ice,
formed by churning magma , its beauty to entice.

Can love be judged by value, of glittered precious stones ?
Or is it just illusion, encrusted with unknowns.
Diamonds are forever, can love become the same ?
To burn forever brightly, with passions to inflame.

Enchantment formed by nascent earth, with stories to unfold,
mystic lore from Roman times, fables to be told.
Birthstone of an April child, gemstone of delight,
so many different faces, for this spectral fey recite.                   

Adornment from antiquity, beauty in a ring,
translucent in its crafted form, enough to make men sing.
Yet theres something that evades me, I need to comprehend,
So heres my simple question.. Are they really girls best friend ?