Wikipedia
Davinciite
Davinciite is a very rare mineral of the eudialyte group, with the simplified formula NaKCaFeZr(SiOOH)Cl. The formula given does not show the presence of cyclic silicate groups. The mineral was named after Leonardo da Vinci to address untypical geometrical forms he tend to use, compared by the authors of the mineral description to untypical (not ideally centrosymmetrical) geometry of the davinciite structure. The other quite untypical feature of davinciite is its lavender colour, while the typical eudialyte is rather pink or red.