|
USA | |
| [Opal-A var. Opal-AN] Manchester, James G. (1931) The Minerals of New York City and its Environs. Bulletin of the New York Mineralogical Club Vol. 3 (1) New York Mineralogical Club |
| [Opal-A var. Opal-AN] Rocks & Min.: 20:61. |
| [Opal-A var. Opal-AN] Jensen (1978) Minerals of New York State |
| John H. Betts (2009) "The minerals of New York City", Rocks & Minerals, 84, 204-240. |
- Manhattan (New York County)
| [Opal-A var. Opal-AN] Alfredo Petrov, field observations on material displaced during hurricane Irene, August 2011. |
| Glenn Rhein |
| [Opal-A var. Opal-AN] King, Van (n.d.) Personal communcation. |
| [Opal-A var. Opal-AN] Rocks & Min.:8:61-65. |
| [Opal-A var. Opal-AN] Manchester, James G. (1931) The Minerals of New York City and its Environs. Bulletin of the New York Mineralogical Club Vol. 3 (1) New York Mineralogical Club |
| [Opal-A var. Opal-AN] Januzzi, 1976. Mineral Localities of CT and Southeastern NY State, p223-224 |
| Jensen (1978) Minerals of New York State, 42-43 (Januzzi, 1966, 1989) (Trainer, 1938). |
| Rocks & Minerals 85:250-259 |
| [Opal-A var. Opal-AN] Manchester, James G. (1931) The Minerals of New York City and its Environs. Bulletin of the New York Mineralogical Club Vol. 3 (1) New York Mineralogical Club |
| [Opal-A var. Opal-AN] Rocks & Min.:11:66 23:712. |
| [Opal-A var. Opal-AN] Manchester, James G. (1931) The Minerals of New York City and its Environs. Bulletin of the New York Mineralogical Club Vol. 3 (1) New York Mineralogical Club |
| Rocks & Min.:8:39. |
| [Opal-A var. Opal-AN] Rocks & Min.: 7:91 8:38. |
| [Opal-A var. Opal-AN] Rocks & Min.: 6:101 & 9:136-137. |
| [Opal-A var. Opal-AN] Rocks & Min.: 8:40. |
| [Opal-A var. Opal-AN] Rocks & Min.:7:148 & 8:40. |
| [Opal-A var. Opal-AN] Manchester, James G. (1931) The Minerals of New York City and its Environs. Bulletin of the New York Mineralogical Club Vol. 3 (1) New York Mineralogical Club |