Assertion: tourmaline | /r/HasProperty | grinded into grain size mixture
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Source sentences:
text: The invention discloses an artificial synthetic tourmaline crystal and synthetic method, which consists 2-10 percent tourmaline and 90-98 percent mineral, wherein the tourmaline and mineral are grinded into grain size mixture less than 15 nm, which is grinded into grain size more than 15 nm after melted at more than 1600 deg.c.