Results of the investigation of caryopilite from goethite-neotocite-rhodochrosite ore of the Mazul manganese deposit, Krasnoyarsk Krai, Siberia, Russia. Caryopilite forms lamellar crystals; optical properties of mineral are following: Ng - yellow, Np - pale yellow, n _m d 1.60, n _g - n _p d d 0.010-0.015. Chemical composition of the studied ñaryopilite corresponds to the empirical formula (Mn _1.95 Mg _1.61 Fe _0.63 ²⁺ Al _0.58 9 _0.23 ) _5.00 [(Si _3.88 Al _0.12 ) _4.00 O ₁₀ ](OH) ₆ , where 9 is vacancies. Concentration of Mg, unusually high for caryopilite, and high content of admixed Al allow to distinguish a new aluminium-magnesium variety of this mineral. It is formed under low temperatures as a result of the replacement of a primary, sedimentary neotocite. It is assumed that at temperature increase Al-Mg-rich caryopilite loses magnesium and aluminium which further concentrate in magnesian-manganese chlorite and spessartine.