1) The document discusses preventive and curative conservation methods for coins in museum collections. It outlines various preventive measures that can prolong the life of coins and reduce deterioration, such as controlling temperature, humidity, light exposure and proper handling and storage. 2) Specific preventive conservation methods are provided for different coin materials like gold, silver and copper. For example, silver coins prone to corrosion require chemical cleaning to dissolve corrosion salts followed by drying and protective coatings. 3) Basic principles of preventive conservation are described, including regular condition checks, monitoring environments, and avoiding factors like poor handling that can damage collections.

1. Care and Maintenance
of Coins
UNIT: V
14. Preventive conservation
15. Curative conservation
Dr.Virag Sontakke
Assistant Professor
A.I.H.C. & Archaeology
Banaras Hindu University,Varanasi

2. Introduction
• Media of Coins
1. Gold
2. Silver
3. Copper
4. Potin
5. Lead
• Copper coins normally develop a green patina.
• Silver coins often develop a black dark patina
• Coins with alloy metals have various corrosion couses

3. Preventive Measures & Curative Measures
• Preservation: Preserve in existing stage by
controlling the factors of decay.
• Conservation: Action taken to prevent further future
decay and to prolong life.

4. Preventive conservation
•Effective preventive conservation reduces the
need for remedial conservation.
•Preventive conservation ensures that the
museum’s collections are displayed, handled,
stored and maintained in ways that do not lead
to damage or deterioration.
•Preventive conservation and security go hand-
in-hand in ensuring the long-term well-being
and safeguarding of collections.

5. Preventive Measures
1. Preventive Measures is Primary work of museum
2. Regular conservation assessment of the museum’s
collections
3. Procedures for monitoring environmental conditions in
stores and displays
4. Building inspection and maintenance
5. Documentation procedures for remedial conservation
programmes
6. Avoid poor handling, packing and transport which is a
major source of damage to collections.
7. A strategy for dealing with disasters and emergencies
like fire, flood, civil unrest, war, earthquakes etc.

6. Basic Principles of Preventive conservation
1. Ensure that all museum staff understand the principles and practice of
conservation.
2. Relative humidity and temperature are kept stable in storage and display
areas
3. Ensuring the light levels are at an appropriate level for items on display
(200 lux)
4. Keeping storage areas clean, tidy and uncluttered
5. Providing sufficient space in storage containers to avoid crushing or
abrasion of items;
6. Not storing items on top of or inside one another;
7. Raising stored items and storage containers off the floor of storage areas
in case of flooding;
8. Making sure that collections are stored in secure areas;
9. Cleaning items only following expert advice;
10. Checking collections on a regular basis, using cotton gloves;
11. Providing appropriate facilities for examining collections for research
and study purposes by staff or visiting researchers;
12. Not smoking, eating or drinking anywhere in the vicinity of collections.

7. Preventive conservation: Methods
1. All coins should be cleaned before being stored.
2. Coins of different metals need different type of care.
3. The storage of coins of different metals in close proximity
of one another shall be avoided.
4. Prolonged exposure of coins to humid environment should
be prevented.
5. Coins should be kept in conditions of low RH.
6. Coins should be stored in inert plastic or metal cabinets or
containers.
7. Placing of de-humidifiers in coins display cases.
8. Dry silica gel, can be used in storage containers to help
provide localised control of RH.
9. It absorbs moisture from the air and helps to achieve a
balanced environment

8. Chemical conservation of coins
Physical
cleaning
Chemical
cleaning
Drying
Preventive
coating

9. Gold
• Theory: Gold is a noble metal: inert, doesn’t react. No
corrosion hence not much treatment
• Physical Cleaning with soft brush & water, detergent, soap
removes the dirt.
• Reetha (Saponin) is the best cleaning solution.
• The shells of reetha soaked overnight in the water and the
clear solution is useful for cleaning.
• Chemical cleaning: washing with dilute HNO3 (Nitric
acid)
• Drying.
• Coating of PVA in Toulene (benzene + methane).
• Should be packed in soft cloth.
• Individual box for each coin is necessary.

10. Silver
• Theory: Silver corrodes when comes in contact with moisture and
air.
• Forms two salts- Silver chloride, Silver sulphide
• Corrosion appears as patina on surface.
• Physical cleaning: with soft brush & water, detergent, soap removes
the dirt.
• Chemical Cleaning: Dissolving of salts in Ammonia. Wash with
Formic acid.
• Drying.
• Test for presence of salts: dilute Nitric acid + Silver Nitrate +
coin = white precipitate.
• Application of PVA (polyvinyl acetate) in Toulene.
• 3 per cent solution of polyvinyl Acetate (sulphur free) makes good
coating.
• Polish: whitening power (dilute of methylene sprit + Amonia)
• Harmful: Plastic, rubber, naphthalene balls (Sulphur content)

12. Copper
• Theory: Corrosive layers of chloride cover the copper
surface. This layer make the metal friable and weak
“Bronze Deceases”. Chloride layer can deteriorate the
metal even after no longer contact with soil.
• Physical cleaning. with soft brush & water, detergent, soap
removes the dirt.
• Chemical cleaning :Sodium hydroxide + Tartaric acid or
Sodium carbonate + Sodium bicarbonate.
• Test for presence of salts: dilute Nitric acid+ Silver Nitrate
+ coin
• Drying.
• Preventive Coating: PVC in Toulene
• Use: Silica gel

15. Other chemical cleaning methods
1. Electro Chemical or Electrolyte Reduction:
• Lead, tin and iron alloyed coin.
• Corrosion reduced by producing hydrogen.
• Coins cleaned by pressure of pipe
2. Ultra sonic reduction:
• leaving the coins in a chemical solution and
• Then treating them by high frequency reduction.
• Long time treatment can harm the coins
3. Mechanical Treatment:
• leaving the coins in a chemical solution
• Using small equipments
• Glass crystal brush, Scalpels ,

16. Archaeological Findings
• If coins found in excavations
• Need to wash first
• Socked them for few days in 10 per cent solution of
sodium sesqui-carbonate.
• Or 5 per cent solution of Rochelle salt
• After wash them in running water.
• Each coin wrapped in clean tissue paper and laced in
separate envelope with all details.
Archaeological Findings

17. Archaeological Findings

19. Display

20. Thank
You