Please be aware that we are closed every Friday in July for fieldwork. Orders and messages will not be processed until the following Monday.


1000ml bottles. PLEASE NOTE THAT THIS PRODUCT MUST BE DILUTED WITH ISOPROPANOL BEFORE USE. We have some bundles available with Pyrite Stop and Isopropanol if you click the dropdown box. 

Prevent and stabilise pyrite oxidation, otherwise known as pyrite disease, pyrite rot, or pyrite decay. Read our guide to treating and storing pyritic fossils by clicking here. This method of preventing and neutralising pyrite decay is a genuine and successful approach, that will help ensure the longevity of your collection. 

Pyrite disease or pyrite decay can completely destroy specimens. In the presence of oxygen, pyrite (FeS2) breaks down to ferrous sulphate (FeSO4) and sulphur dioxide (SO2)Where water or atmospheric moisture is present, sulphuric acid (H2SO4) is also produced as a biproduct.

40% Ethanolamine Thioglycolate. A colourless liquid soluble in isopropanol (isopropyl alcohol). 

  1. Pyrite Stop is alkaline and therefore neutralises and washes out sulphuric acid (a product of pyrite decay)
  2. Thioglycolates react with soluble and insoluble iron compounds, chelates and complex iron, but not stable pyrite. These are the oxidation by-products. This reaction generates a purpley solution of ferrothioglycollate.
  3. It is soluble in ethanol or anhydrous isopropanol – as are the products of pyrite decay. Thus, contact with water (which may be damaging) can be avoided.

Purchase alone or in a bundle with Isopropyl Alcohol. 

You will need to work in a well ventilated environment, wearing full PPE (goggles, gloves, apron, respirator, etc.).

This liquid goes a long way, as it is diluted down with isopropyl alcohol to a 2-5% concentration in Isopropyl Alcohol.

18+ only. Store out of reach from children and animals. 

Subject to Dangerous Goods Shipping Rules. Due to the nature of this product, we are restricted by our couriers to England and Wales mainland shipping only (excludes IOW). We can ship to IOW and Scotland, but surcharges will apply*. Unfortunately, international shipping is not possible at this time. 


*IOW surcharge £11.50+ VAT

*Scottish Lowlands Surcharge £4.50 + VAT

*Scottish Highlands Surcharge £15.50+ VAT

If you are happy to accept these surcharges, process your order as normal and we will be in touch with a payment link for the remaining balance. 

  • Guaranteed safe checkout