Assertion: tourmaline | /r/CapableOf | produce negative ions
Facets:
Source sentences:
text: As we have already mentioned, tourmaline can produce negative ions, far infrared rays and alpha waves all of which can exert powerful healing properties on the body.
text: Tourmaline is a semi-precious mineral which generates only negative ions when heated.
text: Tourmaline is able to produce negative ions while straightening, and the presence of those ions makes it possible to straighten hair with less heat.
text: Tourmaline curling irons contain a mixture of tourmaline, ceramic, jade and titanium, which also produces negative ions.