Assertion: asterism's star | /r/HasProperty | due
Facets:
value: to rutile 'silk'
type: CAUSE
Source sentences:
text: Martin Steinbach (Steinbach--Gems with a Star, Idar-Oberstein, Germany) covered asterism in gems, noting that 50 gem varieties are known to display asterism when cut as cabochons or spheres, and in 90% of the cases the star is due to rutile 'silk'.