1) Transparency 
• (n.) The quality of being diaphanous; transparency; pellucidness.
The quality of of a substance to be seen through. In regard to minerals, it is variable with transparency.
Di`a·pha·ne'i·ty noun [ Confer French diaphanéité . See Diaphanous .] The quality of being diaphanous; transparency; pellucidness. 
diaphaneity Transparency or permitting the passage of rays of light, so that objects may be seen through the substance.
the state or quality of transmitting light; degrees of diaphaneity include transparent, translucent and opaque. 
the quality of being diaphanous; transparency.