Native Silver is a common mineral in many ore deposits, but aggregates of remarkable sizes are nonetheless rare. There is the famous "Silbertisch" of the St. Georg mine in Schneeberg / Saxony : a table shaped 2 x 4 m large, 20 ton aggregate of almost pure silver found in 1427, which Duke Albrecht used as diner table and which yielded 80.000 Mark silver after encoinment. There are also the equally famous wire silver aggregates of the Kongsberg mines in Norway. But the largest single mass of solid silver ever encountered seems to be the so called "Silver Sidewalk" in Cobalt, Ontario
The calm rural Lake Timiskaming community was shattered by the discovery of a rich silver bonanza on August, 7, 1903. Two Railroad workers - J.H, McKinley and Ernest Darragh - found pliable, silvery flakes of metal on the shores of Loog Lake, which soon turned out to be native silver, assaying 4000 ounces to the ton. A new silver rush was on and Cobalt - named after the accompanying cobalt ores - fast became a synonym for fabulously rich silver ore, which needed to just be picked up from the ground.
And so it was indeed. The government geologists, send out for further evaluation, enthusiastically wrote about "pieces of native silver as big as stove lids or cannon balls lying on the ground". There is another story about a fox lurking around at a local forge. The Blacksmith was so annoyed by the fox, that he threw his heavy hammer after the innocent animal. Luckily, the hammer missed the fox, but instead hitted a nearby rock face and exposed a glittering vein of silver, which soon became the famous LaRose mine...By the end of 1905 there were 16 mines in operation and the value of the shipped silver ore exceeded $1.300.000. !
But the largest silver vein was yet to develop. Actually, it was already known. In 1904 a prospecting party of four men discovered a vein of massive native silver along an old portage trail between Kerr Lake and Lake Girout. This so called "Lawson Vein" turned out to be 100 m long. Mining this vein however didnt start before 1908 in earnest, as there was disagreement among the syndicate members about the ownership of the find. When this was finally solved, mining started soon and the vein, which reached up to 0,5 m width was found to continue to a depth of 60 m below surface. Soon it become well known as the Silver Sidewalk and was considered the richest silver vein of its time in Cobalt, which was finally mined out by the above mentioned LaRose Mining Company.
Assuming a length of the vein of 100 m, an overall depth of 50 m and an average vein thickness of only 0,25 m, this is an ore mass of 1250 cubic metres. Assuming a total silver content of 75 % and given an specific weight of 11, this makes an overall weight of more than 10.000 t pure silver ! No wonder, that all four prospectors retired as wealthy men...
Not much was left of this unique silver vein by 1915 and only small bits and samples of it survived to the present
day in candian museums and private collections. The site of the discovery itself is protected nowadays and part of the Cobalt mining heritage trail.