Although the Mammoth had some very rich ore it was not considered a big strike.

In March 1894, they broke ground and were excavating when then found a body of rich ore.

As the richest ores are used up, emissions will rise.

By 1870, it was discovered that there was little rich ore in the district.

By then the richest ore had started to run out; the highest concentrations of silver were found on or close to the surface.

"We found one small pocket of richer ore," said Sniveley.

Test drilling revealed what was then Europe's richest ore.

They believed that concentrations of rich metal-bearing ores might be found there.

They found enough rich ore to justify bringing in more milling capacity, which set off another boom.

A few yards farther on they found broken ore so rich with gold that the rock was more metal than stone.