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$26.00 USD
Price
4657
5

75.4 CTS A GRADE RAINBOW OBSIDIUM SLAB [F5713 ]

SKU
Dimensions (mm)
58.000 x 32.000 x 6.000mm
Weight (cts)
75.400
Type
Rough
Colours

QUALITY ROUGH

A GRADE OBSIDIUM SLAB

This is a piece we cut off a rough specimen at app 45 degree angle to expose the amazing patterns.Great cutting experience.We have taken the photo with the rough wet.

General
CategoryVolcanic glass
Formula (repeating unit)70–75% SiO2, plus MgO, Fe3O4
Identification
ColorDeep black or blackish green
FractureConchoidal
Mohs scale hardness5–6[1]
LusterVitreous
Specific gravity~2.4[2]
Optical propertiesTranslucent
References[3]

Obsidian is a naturally occurring volcanic glass formed as an extrusive igneous rock.

It is produced when felsic lava extruded from a volcano cools rapidly with minimum crystal growth. Obsidian is commonly found within the margins of rhyolitic lava flows known as obsidian flows, where the chemical composition (high silica content) induces a high viscosity and polymerization degree of the lava. The inhibition of atomic diffusion through this highly viscous and polymerized lava explains the lack of crystal growth. Obsidian is hard and brittle; it therefore fractures with very sharp edges, which were used in the past in cutting and piercing tools, and has been used experimentally as surgical scalpel blades. It may contain patterns of gas bubbles remaining from the lava flow, aligned along layers created as the molten rock was flowing before being cooled. These bubbles can produce interesting effects such as a golden sheen (sheen obsidian). An iridescent, rainbow-like sheen (rainbow obsidian) is caused by inclusions of magnetite nanoparticles

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Rest of the world
FedEx is discounted to $39.00 on orders with 2 or more items
Registered Shipping $9.00 / 7 days $16.00 / 21 days
Australia
Registered Shipping is discounted to $9.00 on orders with 2 or more items
Rest of the world
Registered Shipping is discounted to $16.00 on orders with 2 or more items

sedagems
sedagems
Hi Welcome to the Sedagems store, Run by Paul Sedawie and specializing in Australian sapphires and gems stones he has collected on his many buying trips world wide. All stock has a money back guarantee as your continued business is our business.
Mermaid Waters, Australia
Verified
18972 Feedback

  • js20031
    js20031
    Positive

    AAAA+++ Very Happy! Just like the pic.

  • js20031
    js20031
    Positive

    AAAA+++ Very Happy! Just like the pic.

  • wesam
    wesam
    Positive

    Very nice stone

5.00%
Coupon code SEDADEALS
Valid Until
7th Nov 2024

Audit

The Gemstone Sheriff program allows our members to request an audit on any product, which is completed by an independent Gemologist who assesses the accuracy of the item description and pictures.

Shipping Details

Shipping:
$16.00 21 days via Registered Shipping
Ships from:
Australia

Payment Options

  • paypal
  • stripe
This seller adds 10.00% tax to transactions in Australia.

Overview

Listing Type : Standard
Product ID : 492532
Starts : 23rd October 2024 07:49 pm PDT
* All prices are in USD