CZs are very durable and can withstand high temperatures. Cubic zirconias have a very high melting point, so can be fired in kilns with metal clay, a process that would ruin most other gemstones.
The gemological properties of CZs vary by manufacturer due to variances in the type and amount of stablizer used to make isometric (cubic) crystals. Different oxides are added to create colored cubic zirconias. After controlled annealing to ensure the flawless crystals are stable, CZs are cut into faceted gemstones. You can safely clean your cubic zirconias with any jewelry cleaner or detergent. Be sure to rinse well to avoid leaving a residue that would dull the gem's shine.
The greatest challenge for scientists wishing to create CZs was making a crucible that could withstand the temperatures needed to melt and hold zirconium feed powder. In the 1970s, scientists in the U.S.S.R. designed a "skull crucible" that allowed commercial production to take off.