Mineral Evolution Database
Created and maintained by the Mineral Evolution Project in partnership with RRUFF and mindat.
Mineral locality data provided by mindat.org

Ages for Opal at Cheshire Co., New Hampshire, USA

The cyan highlights indicate which age entries were selected as the "best" for assigning the mineral an age of 448Ma - 300.2Ma at this locality

Age range from children

Excel ID	Max Age (Ma)	Min Age (Ma)	Dated Mineral	Minerals explicitely stated as having this age	Age applies to these Elements	Dated Locality ID	Dated Locality	Ref	Ref ID
USGS-U-Th-Pb-01454_207_206	448	448	Zircon			28186	Surry, Cheshire Co., New Hampshire, USA	USGS-U-Th-Pb	USGS-U-Th-Pb
Alexandra-0191	306.6	300.2	Muscovite			16181	Chickering Mine, Walpole, Cheshire Co., New Hampshire, USA	Bradley et al. (2016)	CM54_945

Locality age

Excel ID	Max Age (Ma)	Min Age (Ma)	Dated Mineral	Minerals explicitely stated as having this age	Age applies to these Elements	Dated Locality ID	Dated Locality	Ref	Ref ID
Alexandra-0191	306.6	300.2	Muscovite			16181	Chickering Mine, Walpole, Cheshire Co., New Hampshire, USA	Bradley et al. (2016)	CM54_945
AREPS5_257-00035	171	171				9393	Monadnock Mountain (Mount Monadnock), Jaffrey, Cheshire Co., New Hampshire, USA	Zartman (1977)	AREPS5_257
USGS-U-Th-Pb-01454_206_238	434	434	Zircon			28186	Surry, Cheshire Co., New Hampshire, USA	USGS-U-Th-Pb	USGS-U-Th-Pb
USGS-U-Th-Pb-01454_207_206	448	448	Zircon			28186	Surry, Cheshire Co., New Hampshire, USA	USGS-U-Th-Pb	USGS-U-Th-Pb
USGS-U-Th-Pb-01454_207_235	436	436	Zircon			28186	Surry, Cheshire Co., New Hampshire, USA	USGS-U-Th-Pb	USGS-U-Th-Pb
USGS-U-Th-Pb-01455_206_238	426	426	Zircon			28186	Surry, Cheshire Co., New Hampshire, USA	USGS-U-Th-Pb	USGS-U-Th-Pb
USGS-U-Th-Pb-01455_207_206	447	447	Zircon			28186	Surry, Cheshire Co., New Hampshire, USA	USGS-U-Th-Pb	USGS-U-Th-Pb
USGS-U-Th-Pb-01455_207_235	430	430	Zircon			28186	Surry, Cheshire Co., New Hampshire, USA	USGS-U-Th-Pb	USGS-U-Th-Pb

Locality age (remote)

Excel ID	Max Age (Ma)	Min Age (Ma)	Dated Mineral	Minerals explicitely stated as having this age	Age applies to these Elements	Dated Locality ID	Dated Locality	Ref	Ref ID
AREPS5_257-00014	171	171				220659	Monadnock Mountain (Mount Monadnock), Lemington, Essex Co., Vermont, USA	Zartman (1977)	AREPS5_257