Geology Superstore
Geology Superstore


£1.61£4.23 ex VAT



Obsidian is an extrusive igneous rock, these specimens exhibit a typical black colouration with conchoidal fractures, they come from South East Mexico and are excellent for educational use and collectors due to the quality. This igneous rock forms when magma extrudes onto the earths surface, chemically it is silica rich and impurities give the black colouration. It’s fine crystalline texture and fracture makes obsidian appear glassy and it breaks as such. The pieces are available in various sizes and come supplied in a card tray with an information label.

  Hurry up! Sale end in:
  •  Delivery & Return


    We ship to all 50 states, Washington DC.
    All orders are shipped with a UPS tracking number.
    Always free shipping for orders over US $200.
    During sale periods and promotions the delivery time may be longer than normal.


    Elessi will accept exchanges and returns of unworn and unwashed garments within 30 days of the date of purchase (14 days during the sales period), on presentation of the original till receipt at any store where the corresponding collection is available within the country of purchase.

    Your return will usually be processed within a week to a week and a half. We’ll send you a Return Notification email to notify you once the return has been completed.
    Please allow 1-3 business days for refunds to be received to the original form of payment once the return has been processed.


    Give us a shout if you have any other questions and/or concerns.
    Phone: +1 (23) 456 789

  ... people are viewing this right now
Guaranteed Safe Checkout

Obsidian is a natural volcanic glass, an extrusive igneous rock, it is produced when silica rich lava extruded from a volcano rapidly cools minimising crystal growth which gives the rock a fine, glassy texture. It is commonly found within the margins of rhyolitic lava flows known as obsidian flows, its high silica content (70 -75%) produces a highly viscous lava with some degree of polymerization. The inhibition of atomic diffusion through this highly viscous and polymerized lava explains the lack of crystal growth. It is hard and brittle rock with a black appearance due to the presence of conchoidal fractures, it therefore breaks with very sharp edges. It is this particular feature which has made obsidian an important rock in human history and evolution and why it is so well known and popular, as the sharp edges allowed it to be used in the past in cutting and piercing tools, most notably, arrow and spear heads. It has been used experimentally as scalpel blades in the past and recent years. These particular samples come from South East Mexico, the pieces will display typical black colouration and conchoidal  fractures, making them suitable for both collectors, enthusiasts and educational use. Each sample will come supplied in a card tray with an information label.

Weight 130 g
Specimen Size

2" x 2", 3" x 2", 4" x 3", Thin Section Slide

Based on 0 reviews

0.00 Overall
Be the first to review “Obsidian”

Your email address will not be published. Required fields are marked *


There are no reviews yet.

SKU: IGNROK039 Categories: ,
Close My Cart
Close Wishlist
Recently Viewed Close