Zirconium is found in the Earth's crust, 0.023 % (w/w), in the minerals zircon, malacon, baddeleyite, ziekelite, eudialyte and rare earth minerals in mozanite sand . The isotopes found in nature are 90Zr (51.46 %, stable), 91Zr (11.23 %, stable), 92Zr (17.11 %, stable), 94Zr (17.40 %, stable) and 96Zr (2.80 %, stable) .
In pure form, zirconium occurs in the following crystal forms:
α-form: Hexagonal crystal at < 865 °C 
β-form: Body-centered cubic at > 865 °C