sand - quartz - angular grained beach sand, primarily quartz, from Zuma Beach, Malibu, California - set of two 2-ounce jars Geode slices from Brazil are

Geode slices from Brazil are also altered by dying them in unnatural shades of red or blue

is a topic still under discussion

with one that is cemented with calcium carbonate

This sand is roughly half garnet and half quartz

sand - quartz - angular grained beach sand, primarily quartz, from Zuma Beach, Malibu, California - set of two 2-ounce jars Geode slices from Brazil areThis sand is particularly interesting because of the angular nature of the quartz grains. As sand is transported down streams, feldspar disintegrates and weathers to clay. Quartz is resistant, so the sand delivered to the mouths of streams is frequently quartz rich, as is this sand. The grains become rounded as they are transported along the stream channel. The angular nature of these grains shows that transport was short. This sand provides an