Obsidian, medium size specimen

$20.00 inc GST

Medium Obsidian specimen for the classroom from the Tarawera volcanic eruption of 1886 in the Bay of Plenty Region, New Zealand.

Formed during the eruption of Mt Tarawera near Rotorua in June 1886 at the margins of rhyolitic flows.  Contains pumice and perlite inclusions formed by contact with groundwater.

In the classroom explore differences in structure compared to other rocks from felsic lava such as pumice and rhyolite.

Colour: black to black/green

Fracture: conchoidal

Mohs hardness :5-6

Specific gravity: ~2.4

Specimens are usually no smaller than 80mm in one dimension.

Out of stock

Category: Tags: ,

Description

Medium Obsidian specimen for the classroom from the Tarawera volcanic eruption of 1886 in the Bay of Plenty Region, New Zealand.

Formed during the eruption of Mt Tarawera near Rotorua in June 1886 at the margins of rhyolitic flows.  Contains pumice and perlite inclusions formed by contact with groundwater.

In the classroom explore differences in structure compared to other rocks from felsic lava such as pumice and rhyolite.

Colour: black to black/green

Fracture: conchoidal

Mohs hardness :5-6

Specific gravity: ~2.4

Specimens are usually no smaller than 80mm in one dimension.

Reviews

There are no reviews yet.

Only logged in customers who have purchased this product may leave a review.

You may also like…