In this task you will be given a text passage from a trivia quiz. You should choose the category this question belongs to from these categories: History, Science, Social Science, Fine Arts, Literature. You can only choose one category, so if in doubt, please choose the closest match.

Bloodstone, agate, and onyx are chalcedonic varieties of this mineral. Other color variations arise from substituting atoms for silicon; iron for citrine and amethysts, titanium for the rose variety. When cemented it makes sandstone and when fused, silica glass. For ten points, identify this mineral composed of crystalline silicon dioxide.
Science