During the 1991 season, a small blasthadexposed a nice-looking vein in one side of an old tunnel. The tunnel had tobewidened to accommodate the mine's underground machinery. By chance,acrewmember, Graham Sutton, chose to blast the right side of thetunnel, insteadof the left; thus exposing the vein.
In 1992, the new vein was mapped, studiedand finally chosen as a goodtarget for exploration. Unfortunately, afterfinding very little during theprevious year, both budgets and attitudes weredrawing thin. The money wasalmost gone, and mine closure was being considered.Under this stress, a tunnelwas started on the new vein. It contained a largequantity of tetrahedritecrystals and became known as the Tetrahedrite Vein.After several weeks, somesmall pockets were discovered on this vein leading thecrews to believe thatthey were on to something.
By August, patience paidoff. On August 21,at 3:00 p.m. a blast opened up a small hole. Inside, thecontents were arrayedin every color of the rainbow as rhodochrosite crystalsto 15 cm littered theinterior. Within one hour, a 15 cm crystal had beencollected. All was caught onvideotape by the Denver Museum of Nature andScience as one rhodochrositetreasure after the next was pulled from thepocket.
Several weeks later, the pocket was empty.The 15 cm crystal was repaired onto its pocket matrix and became known as the'Alma King', the largestcomplete rhodochrosite in the world. Over a 1000specimens were ultimatelyrecovered from the 'Rainbow Pocket'.
The pocket saved the mine and allbecause aminer chose to peel one side of an old mine tunnel instead of theother; a 50/50decision that lead to the success of the Sweet Home Mine. The'King' is onpermanent display at the Denver Museum of Nature and Science, in Denver,Colorado.