Microscope view: 40x

Name: basalt

Color(s): dull black

Shape: irregular shape, angular

Texture: rough with relatively sharp edges

Size of crystals: relatively small, not easily seen with the naked eye. They appear as little speckles on the microscope view.

Other observations: does not leave particles on fingers, odorless

Microscope view: 40x

Name: granite

Color(s): black, greenish gray, white. Some crystals are shiny while others are dull.

Shape: irregular shape, angular

Texture: rough with edges which are less sharp

Size of crystals: very big, easily seen with the naked eye. They appear as wide slabs on the microscope view.

Other observations: does not leave particles on fingers, slight metallic smell was observed on some samples

Name: obsidian

Color(s): shiny black, some samples have brown stripes.

Shape: irregular shape, angular

Texture: smooth as glass with edges which are very sharp

Size of crystals: obsidian has no crystals. No microscope view is shown because no crystals are present.

Other observations: does not leave particles on fingers, has concentric half-circle ridges on some surfaces which are characteristic of broken glass