According to the IPRA, the object was examined by the University of Georgia and determined to be made of lizardite, and IPRA claims that the object has Chinese characteristics:
A claims that the object has Chinese characteristics:
Preliminary opinions on the form and motifs have been identified as first appearing in the Chengdu plain of the Sichuan basin in Southwestern China. The distinctive eye cartouches and pronounced eyes found on the Taotie(?) [i.e. Chinese ogre] faces on the cross guard and those on the "head" on the handle, are stylistic duplicates of those first appearing with the Sanxingdui culture (1750-1200 BCE). […] It should be noted that at this time, we are not aware of a similar eye motif in North America art. The eyebrow motif, pronounced eyes, volute shape fangs and diagonal cross-hatching of the character on the cross guard, are stylistic equivalents to some depictions of the Mesoamerican rain deity. The similarities of Olmec art and other cultural attributes to ancient China has long been a subject of scholarly debate.
The shape of the dagger’s blade is also a bit unusual, though it is similar to a Chinese dagger that appeared in the video game Far Cry 3 at the end of 2012. Unfortunately, I don’t know enough about ancient Chinese art to have a more developed opinion of it.
Haskill goes far beyond even this meager evidence and suggests that Chinese and Olmec art are so similar as to have a connection, and claims that the Chinese gave the Olmec their culture and their social system—including social stratification and aristocracy. This seems to be an echo of the old claims made about Fusang, based on a spurious reading of a mythical Chinese land as Mexico.