Clear Fused Quartz:

This is the most effective general purpose quartz available. It is a high quality quartz made from natural quartz sand. Because it is made from natural resources, it does contain impurities. The impurities may cause broad band absorption if the quartz should solarize. Solarization appears as a purplish film over the length of the lamp. The chart below represents the transmission properties.

Synthetic Fused Quartz:

This is a synthetic quartz grown from SiCl₄. It is volatilized in a oxygen flame, or, if a hydroxyl free quartz is needed, it is formed by electrical arc in an oxidizing atmosphere. This quartz does not solarize because of the absence of ionic impurities normally associated with Clear Fused Quartz. The chart below represents the transmission properties.               

Cerium Doped Quartz:

This is a flame fused natural quartz mixed with 6% Cerium oxide. The natural sand is highly refined and does not solarize. This is typically used in Nd:YAG systems. The chart below represents the transmission properties.

Titanium Doped Quartz:

This is also known as Ozone Free Quartz. It has the ability to block some UV light and it's production of ozone. This is an electrically fused natural quartz mixed with 3% Titanium oxide and made from highly refined natural quartz sand to prevent solarization. The transmission chart below represents the transmission properties.