yellow quartz... Brazil

Thats a beautiful specimen.  I bet it would look awesome with light shining through it.

i dont know... it doesnt look like a "normal" citrine color to me... is all yellow quartz citrine??...

It would be easier to tell I think if it were backlit by the sun or comparable white light.  If there are yellow inclusions reflecting yellow throughout the crystal then backlighting might supress this internal reflection and allow us to see the true color of the crystal.

Also keep in mind that much, if not all, of the citrine from Brazil is heated treated amethyst.  Although the color is usually orange, to brown red.  The pale yellow or pale orange varieties or more likely natural citrine.  This looks like it has the potential to be natural citrine if the yellow is actually coming from the crystal.