Gold Nugget Found In Australia Turns Out To Be A 4.6 Billion-Year-Old Meteorite

DaveHolecouldnotpryopentheheavyandreddishrockhefoundinMaryboroughRegionalPark.Gemologisteventuallyrealizedtheobjectisa4.6billion-year-oldmeteorite.(MuseumsVictoria)

DaveHolediscoveredsomethingextraordinarywhilediggingforgoldinMaryboroughRegionalParknearMelbourne,Australia,in2015.Withthehelpofametaldetector,hefoundaheavyandreddishrocklyingonayellowclay.

ExtremelyHardAndHeavyRock

Holewashopingtofindagoldnuggetinsidetherockbecausetheobjectwasheavierthanitlooked.MaryboroughisalsointheGoldfieldsregion,wheresignificantgoldminingoccurredinthe19thcentury.

Despitenumerousattempts,however,Holefailedtoopentherock.Heusedarocksaw,adrill,ananglegrinder,anacid,andevenasledgehammer,butnothingmadetheobjectcrack.

Henonethelesskepttheobject.Itwasyearslaterthathefoundoutthattherockwasmorevaluablethanhethought.Itissomethingrarerthangold.

4.6Billion-Year-OldMeteorite

Intriguedbyhisfind,HolecontactedtheMelbourneMuseumtofindoutwhatitreallywas.ItdidnottakelongformuseumgeologistsDermotHenryandBillBirchtorealizetheobjectissomethingfromoutofthisworld.

"Ithadthissculpted,dimpledlooktoit,"Henrysaid."That'sformedwhentheycomethroughtheatmosphere,theyaremeltingontheoutside,andtheatmospheresculptsthem."

TestingconfirmedthatHole'sgoldnuggetwasinfacta4.6billion-year-oldmeteoriteandhasbeencalledtheMaryboroughmeteorite.

ThespacerockissoheavybecauseunlikerocksonEarth,itispackedwithverydenseformsofnickelandiron.

SilverRaindropsFromBirthOfTheSolarSystem

Thegemologistsusedasuper-harddiamondsawtosliceofftheedgeoftherockwhichrevealedlittlesilverraindrops.Thesewereoncedropletsofsilicatemineralsthatcrystallizedfromthesuper-hotcloudofgasthatformedthesolarsystem.

Analysisalsorevealedthattherocklacksweathering,suggestingthatithadbeenonEarthforlessthan200years.

"Thereisnoevidenceforanyshock-inducingeventandthemeteoriteshowsincipientweatheringintheformofthiniron-oxidemantlesaroundtheFe-Nigrains.Aterrestrialageoflessthan1,000yearsisestimatedfromC14dating,"thegemologistsreportedintheProceedingsoftheRoyalSocietyofVictoriaonJuly17.

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