where hot springs stream or spout above the surface, when the silica
and lime impregnated water, reduced in heat and released from pressure,
begins forthwith to deposit the minerals previously held in solution.
Hence the formation of the wondrous Pink and White Terrace, destroyed
by volcanic action some eight years since, which grew almost while
you watched; so rapidly was the silica deposited that a dead beetle or
ti-tree twig left in the translucent blue water for a few days became
completely coated and petrified.

Gold differs in its mode of occurrence from other metals in many
respects; but there is no doubt that it was once held in aqueous
solution and deposited in its metallic form by electro-chemical action.
It is true we do not find oxides, carbonates, or bromides of gold in
Nature, nor can we feel quite sure that gold now exists naturally as a
sulphide, chloride, or silicate, though the presumption is strongly
that it does. If so, the deposition of the gold may be ceaselessly
progressing.

Generally reef gold is finer as to size of the particles, and, as a
rule, inferior in quality to alluvial. Thus, in addition to the extra
labor entailed in breaking into one of the hardest of rocks, quartz,
the _madre de oro_ ("mother of gold") of the Spaniards, there is the
additional labour required to pulverise the rock so as to set free the
tiniest particles of the noble metal it so jealously guards. There is
also the additional difficult operation of saving and gathering together
these small specks, and so producing the massive cakes and bars of gold
in their marketable state.

Having found payable gold in quartz on the surface, the would-be miner
has next to ascertain two things. First, the strike or course of the