German Dramatist of Wilhelm Tell and Maria Stuart
Puzzle 17 of Sailing Hard Pack
Question is: German Dramatist of Wilhelm Tell and Maria Stuart
and the answer is: SCHILLER
Word Meaning:
SCHILLER — (mineralogy) A lustre, similar to sheen, observed in certain minerals, such as hypersthene or labradorite, due to the presence of minute parallel inclusions.
Definitions from Wiktionary.