Quarzite

Rock without a past

01

The history of this rock is so long and complex that it cannot be reconstructed.

02

It is a quartzite, a rock made entirely of quartz, a mineral with a composition that is similar to that of glass.

03

This rock arrives in the form of pebbles, transported from a glacier that has now completely receded.

04

We know that the rock from which the pebble broke was subjected to high pressure and temperatures.

05

The high pressure and temperatures have dictated the shape of the crystals of quartz – not well contoured but rather irregular, and their nuanced colours indicate strain. We don’t know how the quartz appeared before becoming so distorted. Maybe it crystallised slowly in the crust and formed a magmatic seam, or maybe it was the amalgamation of grains of sand on a beach or in a desert dune. We don’t know how old it may be.

If we want to dream, difficult rocks are the best…..

Name: Quarzite
Type of rock:

Metamorphic rock

Minerals: Quartz
Fossili: assenti
Location: Lazise (N 45° 30′ 39.3″ E 010° 46′ 25.6″)

Formation (deposit):

Formation (pebble):

pebbles of the glacial deposits of the sarca (morainic amphitheater of the Garda)

unknown

Age (deposit):

Age (pebble):

Pleistocene (less than a million years)

unknown

How the pebble was formed:

How the rock was formed:

on the front of a lowland glacier

unknown

curiosity

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