Robertsite

Source: Wikipedia, the free encyclopedia.
Robertsite
2V angle
Measured: 8°
References[2][3][4]

Robertsite, Ca3(Mn3+)4[(OH)3| (PO4)2]2·3(H2O) (alternatively formulated Ca2(Mn3(PO4)3O2)(H2O)3), is a secondary

South Dakota School of Mines in Rapid City, South Dakota
.

The type locality for Robertsite is the Tip Top mine,

monoclinic
mineral.

It occurs as a secondary mineral in

Omo Valley of Ethiopia it occurs with mitridatite associated with fossil fish in Pliocene/Pleistocene lake sediments.[5]

Recently, in an exploration conducted by the Italian La Venta Geographical Association, confirmed the existence of Robertsite in the Puerto Princesa Subterranean River National Park, located about 50 kilometres (31 mi) north of the city center of Puerto Princesa, Palawan, Philippines.[6][7]

  • Mitridatite group:
    • Arseniosiderite-mitridatite series:[8]
      • Ca2(Fe3+)3[(O)2|(AsO4)3]·3H2O
      • to
      • Ca2(Fe3+)3[(O)2|(PO4)3]·3H2O
    • Arseniosiderite-robertsite series:[9]
      • Ca2(Fe3+)3[(O)2|(AsO4)3]·3H2O
      • to
      • Ca3(Mn3+)4[(OH)3|(PO4)2]2·3H2O

References

  1. S2CID 235729616
    .
  2. ^ Robertsite: Mindat.org
  3. ^ a b c Handbook of Mineralogy
  4. ^ Webmineral data
  5. ^ Mindat location data
  6. ^ Mendoza, Shielo. "Why Puerto Princesa's underground river deserves to win". Yahoo! Southeast Asia Newsroom. Retrieved November 10, 2011.
  7. ^ Villamente, JIng. "$5B income seen from Wonders of Nature win". The Manila Times.net. Archived from the original on 13 November 2011. Retrieved 10 November 2011.
  8. ^ Mindat Arseniosiderite-Mitridatite Series
  9. ^ Mindat Arseniosiderite-Robertsite Series