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



The Mineral Evolution database is currently under development.

The goal of this page is to present localities at which the mineral is found, and estimates of the oldest possible geologic age of the minerals at these localities.


Locality Name:
Hernwood, Baltimore Co., Maryland, USA


mindat Locality ID: 251708
mindat URL: http://www.mindat.org/loc-251708.html

Tectonic Settings:

Total number of sublocalities beneath "Hernwood, Baltimore Co., Maryland, USA": 1
Total number of bottom-level sublocalities: 1

Number of Child Localities: 1
Child Localities:
Marriottsville Quarry

Latitude: 39°22'27"N
Longitude: 76°52'2"W
Decimal Degree (lat, lon): 39.374166666667,-76.867222222222
AThis mineral is Anthropogenic.
GThis mineral is directly dated.
BThis mineral is reported as having this age.
YThis mineral is using an age reported as an element mineralization period.
OThis mineral is using an age calculated from all data at the locality.
RThe age displayed for this mineral originates from a different, non-child locality.
PThe age displayed for this mineral is the range of ages for this mineral at all of this locality's children.
This mineral's age has not yet been recorded.

This Mineral list contains entries from this locality, including sub-localities. Minerals in bold are reported by mindat.org as occurring directly at this locality, and do not occur at any children (sublocalities) of this locality.

Elements at this locality, including sub-localities: Al B C Ca Cu Fe H K Mg Na O S Si Ti 

Elements from minerals reported directly at this locality: 

Structural Groups for minerals in this locality: 
AmphiboleCalciteChalcopyriteClayFeldsparMicaNickelineNonePyritePyroxene
QuartzRutileTalcTourmaline

16 IMA Minerals at location:
Calcite  (*)Chalcopyrite  (*)Diopside  (*)Dolomite  (*)Dravite  (*)
Graphite  (*)Microcline  (*)Muscovite  (*)Phlogopite  (*)Pyrite  (*)
Pyrrhotite  (*)Quartz  (*)Rutile  (*)Schorl  (*)Talc  (*)
Tremolite  (*)
Mineral nameStructural GroupsIMA FormulaMax Age (Ma)Min Age (Ma)# of Sublocalities containing mineralLOCALITY IDs, not mindat ids# of localities containing mineral
Calcite  (*)CalciteCa(CO3)121846527770
Chalcopyrite  (*)ChalcopyriteCuFeS2121846527198
Diopside  (*)PyroxeneCaMgSi2O612184654135
Dolomite  (*)NoneCaMg(CO3)212184659895
Dravite  (*)TourmalineNaMg3Al6(Si6O18)(BO3)3(OH)3(OH)1218465648
Graphite  (*)NoneC12184652812
Microcline  (*)FeldsparK(AlSi3O8)12184654924
Muscovite  (*)Mica ClayKAl2(Si3Al)O10(OH)2121846517380
Phlogopite  (*)Mica ClayKMg3(AlSi3O10)(OH)212184652273
Pyrite  (*)PyriteFeS2121846539462
Pyrrhotite  (*)NickelineFe7S812184659056
Quartz  (*)QuartzSiO2121846561156
Rutile  (*)RutileTiO212184655614
Schorl  (*)TourmalineNaFe2+3Al6(Si6O18)(BO3)3(OH)3(OH)12184652705
Talc  (*)Clay TalcMg3Si4O10(OH)212184653337
Tremolite  (*)Amphibole   Ca2(Mg5.0-4.5Fe2+0.0-0.5)Si8O22(OH)212184652562


No ages have been assigned to this locality yet.

All locality data graciously provided by mindat.org

All age data...

Other copyright data...