Name 1
EPSOMITE
Name 2
/
ID number
002.22.Idrija
Manager / Administrator
Idrija Mercury Heritage Management Centre
Ownership
Public
Owner
Republic of Slovenia
Local / Original ID Number
368 M–16, (samples from M–16/1 to M–16/7)
Type of Object
Ore deposit

Description

Short description
On grey enclosing rock there are up to 6cm long, white fibrous crystals of epsomite. The sample is very brittle and crumbly.
Measures
Length 14 cm, width 11 cm, height 7 cm.
Materials
Epsomite mineral
Dating
The time of creation is unknown
Author / Producer
/
Picture attachments
Original use
Epsomite (MgSO4•7H2O), is a very common and typical secondary mineral of Idrija ore deposit. It was first described by J.A. Scopoli back in 1761. It is growing from the fractures on the wall of abandoned pit tunnels, where the oxidation of iron sulfides and the dissolution of magnesium in higher positioned dolomite (dedolomisation process) is occurring. The sulfates also originate in gypsum, found in several levels in the ore deposit. Epsomite is most frequently found in a form of fibrous crystals, sinter and flowstone. Its hardness is between 2 and 2.5, its density between 1.7 and 1.8g/cm3. Epsomite is in a different white colour. In rare occurrences it is translucent or even silver. The fibrous shape of epsomite has a silk shine. It grows several centimetres in length, however the longest were also up to two metres long. The miners named the nicest fibrous crystals as “perkmandelčeva brada” (beard of a mining elf called Perkmandeljc).
Present use
The epsomite sample is being preserved, secured and presented as important natural heritage of Idrija ore deposit with exceptional universal values. It represents a unique soil “archive”, as the sample was excavated in Idrija ore deposit and also stored. It is a part of the thematic collection “Minerals of Idrija ore deposit” of the Mine Geological Collection, displayed in the CUDHg administrative premises, as a part of the Francis’ shaft.
Original location
In all parts of Idrija ore deposit, mainly in the top and middle pits (from the II to the IX levels). The largest and nicest epsomite formations were found on the IV, VI, VII and the IX levels of the Idrija Mine.
Present location
CUDHg (Mining Geological Collection), Bazoviška 2, SI-5280 Idrija

STATE OF CONSERVATION

History of conservation:
The sample is appropriately preserved. Additional interventions are not necessary. Security of the premises is taken care of.
Present state
good
Necessary activities:
Regular seasonal maintenance.

DOCUMENTATION

Addresses / collections / links etc. where further in-depth information is accessible:
- CUDHg Inventory Book;
- Čar, Jože. Rudniška geološka zbirka: Seznam in opis vzorcev. Mercury Mine Idrija, 2003, p. 1–122, [material is kept in the CUDHg archive];
- Vidrih, Renato, Mikuž, Vasja, Peljhan, Martina, Klemenčič, Tomaž. Minerali idrijskega rudišča. Proteus, 57/7, 1995, p. 269‒276;
- Vidrih, Renato, Mikuž, Vasja. Minerali na Slovenskem. Ljubljana: Tehniška založba Slovenije, 1995;
- Rečnik, Aleksander. Minerali živosrebrovega rudišča. Ljubljana: Institut "Jožef Stefan"; [Salzhemmendorf]: Bode, 2012.
Submitted
Mestni muzej Idrija
Submitted by
Miha Kosmač
Date Submitted
28. 2. 2018
Date Edited
Never