Which is the crystalline form of silica

Which is not a crystalline form of silica?

Which of the following statements are true about quartz, A) it is pure crystalline form of silica B) it is a tetrahedral polymer of SiO_(2) C) UV light can pass through quartz

Which of the following is a crystalline form of silica ?

Name the following : The crystalline form of silica used in modern radio and T.V broadcasting and mobile radio communication.

Name three important crystalline forms of silica.

Name three important crystalline forms of silica.