Aztec ritual knife, photographed at the British Museum on October, 30 – I’m the shadow on the right. The image links to the museum’s website page that describes the object and provides sharper – but less personal -images.
The minute description of the materials is valuable, but the statement that this knife is too fragile and therefore should have been used only in a symbolic way seems unsustainable to me.
Just think of the many bloodshed rituals, well documented in the Mesoamerican traditions, which require the use of a sharp blade, but not particularly robust.
Experience shows that the Ritual procedures can unnaturally disintegrate or confer an equally unnatural resistance to the instruments involved, so I would not rule out that this knife has been used more vigorously. But, to the casual Eye, I would say that it has been used.