Task: Text Categorization
Input (English): Synthetic varieties of this mineral were made by Auguste Verneuil using the flame-fusion process. Asterism in this mineral is caused by the inclusion of rutile. One variety of this mineral has a shade known as Kashmir blue, and another variety has a shade called pigeon's blood. The material emery consists of magnetite and this mineral. Aluminum oxide occurs naturally in large deposits as this mineral, which has a value of nine on the Mohs scale of hardness. For 10 points, name this mineral whose transparent varieties, such as sapphire and ruby, are used as gems.
Output (English): Science