This presentation is prepared for the MA students to get basic and general information on the subject. This presentation is incomplete and students advised to get the further and proper information from subjective and recommended books and research articles.

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. Care
and
Maintenance
of Coins

3. 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

4. Coins
1. Gold: Noble metal
2. Silver: It is also a noble metal because it resists corrosion
and oxidation, though not like gold
3. Copper: It is soft, malleable, component of various metal
alloy. Copper is one of the few metals that can occur in
nature in a directly usable metallic form
4. Potin: Also known as billion. It is typically a mixture
of copper, tin, lead and silver ? (in varying proportions)
5. Lead: Lead is soft and malleable, and also has a
relatively low melting point

5. Indian Coinage
S.
No.
Coin Type Metal Details inscribed Script and language
1.
Punch-marked
coins
Mostly silver,
sometimes copper
Mostly geometrical
shapes, plants, animals,
and geographical features
None
2. Indo Greek type Mostly silver
Name of the issuing ruler
with depicting legends
The language was
Prakrit, mostly in
Kharoshthi script
3. Kushana type
Mostly gold, but
also silver and
rarely copper
Figure, name, and title of
the ruler on obverse, and
the deities on the reverse
Legends in Greek,
inscribed in Kharoshthi
script
4. Gupta coinage
Mostly gold coins
were issued,
silver and copper
A figure of the ruler, with
a deity
Brahmi
5. Chola coins
Gold, silver and
copper
Legends of the rulers Nagari script
6. Post Gupta
Decline in gold,
mostly silver and
Names of the rulers, and
a motif
Varied with dynasties.

9. Potin

10. Lead

11. Preventive Measures & Curative
Measures
• Preventive measures
(Preservation):
• Preserve in existing stage
by controlling the factors
of decay.
• The process of stopping or
slowing deterioration of
objects.
• It not involve actual
treatment.
•Curative Measures
(Conservation):
• Action taken to prevent
further future decay and to
prolong life.
• The process to preserve
material/s minutely to
bring back to original
shape and condition as
possible.
• Laboratory work

12. Preventive Measures
1. Preventive Measures is Primary work of museum
2. Effective preventive measures increase the life of the object
3. It ensures that museum objects not lead to damage or
deterioration.
4. Procedures for monitoring environmental conditions in
stores and displays
5. Building inspection and maintenance
6. Documentation procedures for remedial conservation
programmes
7. Avoid poor handling, packing and transport.
8. Dealing with disasters and emergencies like fire, flood, civil
unrest, war, earthquakes etc.

13. Classification of Museum Objects
• Organic Objects
• In-organic objects
• Organic decays with the passage of time.
• In-organic materials decay process is slower than
organic
• a) Organic materials are paper, wood, textiles,
leather, ivory, bone etc.
• b) In-organic materials are ceramic, stone, metal etc.

14. Deterioration Causes
1. Dust
2. Direct sunlight
3. Constant heat
4. Climatic conditions
5. Environment of the building
6. Light
7. Micro-organisms like fungi, insects, termites etc., in the
atmosphere.
8. Mis-handling of objects
9. Bad storage
10.Fire or accidents.

15. 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. Dry silica gel, absorbs moisture from the air and helps to
achieve a balanced environment

16. Climate
• Humidity and temperature are two most important components
of the climate.
• Humidity and temperature are interrelated.
• The relative humidity increases if there is a drop in temperature.
• The relative humidity decreases if the temperature is raised.
• High humidity favours rapid reproduction of insects and micro-
organisms like fungi.
• The presence of water deteriorates metal much faster then under
dry condition.
• Most often climatic condition also damages objects.
• Viz. Any objects becomes adjusted to a particular balance of
relative humidity, and transported to a different climate, tend to
suffer damage

17. Monitoring humidity and
Temperature
• Maintain a same climate.
• Check the temperature throughout the year
• It is recommended that:
• The relative humidity should range between
(45%) to (60%) and
• The temperature between 20 to 24 degree
Centigrade (68 to 76 F)
• Air-conditioning norms are chosen according to
the outside condition of climate of the museum
• The air-conditioning that it must run
continuously day and night.
• Fluctuation in AC can harm the objects. For
example,
• Metal objects will start corroding.
• Record the temperature and humidity of all the
rooms and galleries via installing hydro
thermometer.

18. Light
• Light poses a threat to the object.
• Although normally not sensitive for metal.
• The control for light must observe following three
factors:
1. Minimize the intensity of light falling upon the
objects
2. Expose objects to the light for a minimum period
of time

19. Fire
• Fire is one of the major danger
• Its harmful for museum.
• The protection measures against fire should be taken in
following ways:
• While the planning the building by keeping
provision for appropriate exits door for quick
evacuation of the staff as well as the visitors.
• Easy availability of water supply
• Installations of electronic items should be of best
quality
• Fire extinguish should be installed
• Installation of fire detector

20. Water
• Water causes serious damage to the objects.
• Objects get highly susceptible to contact with water and
can be severely damaged by even brief contact.
• Its harmful for organic and in-organic items

21. Care
1. Collection and storage must be handled safely.
2. Correct levels of heat and humidity: full air conditioning;
improvised micro climate
3. Well planned storage areas
4. Protection from light: correct levels of light; blind and dark
curtains
5. No water seepage
6. Full instructions to the users of collections; clean hands,
correct handling
7. No smoking,
8. No pens or inks
9. Cleanliness
10. Use replica instead originals (in case of rare)

22. Basic Principles of Preventive conservation
1. Trained staff.
2. Relative humidity and temperature need stable
3. Ensuring the light levels (200 lux)
4. Storage areas clean, tidy and uncluttered
5. Providing sufficient space
6. Not storing items on top of other
7. Flooding provisions
8. Safety and security
9. Expert advice (Cleaning)
10. Regular inspections
11. Handle with Care
12. Not smoking, eating or drinking

24. De-Humidifiers

25. Dry silica gel

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

29. 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.

31. Physical cleaning: with soft brush & water, detergent, soap for removing the dirt.

32. soaked overnight in the solution of water + Reetha

33. Chemical cleaning:
washing with dilute HNO3 (Nitric acid)

34. Coating of PVA in Toulene (benzene + methane).

37. Silver
• Theory: Silver corrodes when comes in contact with moisture
and air.
• Forms two salts- 1) Silver chloride, 2) 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 + Ammonia)
• Harmful: Plastic, rubber, naphthalene balls (Sulphur content)

38. Patina of Silver chloride, Silver sulphide

39. Physical cleaning: with soft brush & water, detergent, soap for removing the dirt.

40. Chemical Cleaning: Dissolving of salts in Ammonia and
Wash with Formic acid.

41. • Application
of PVA
(polyvinyl
acetate) in
Toulene.
• 3 % solution
of Polyvinyl
Acetate
(sulphur
free) makes
good
coating.

42. Polish: (Dilute of methylene sprit + Ammonia)

43. Copper
• Theory: Corrosive layers of chloride cover the copper surface.
• This layer make the metal powdery 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

45. Physical cleaning: with soft brush & water, detergent, soap removes the dirt.

46. Chemical cleaning:Sodium hydroxide + Tartaric acid or Sodium carbonate + Sodium bicarbonate.

47. Test for presence of salts: dilute Nitric acid+
Silver Nitrate + coin

48. Lead
• Lead coins are limited in India.
• Basic lead carbonate and lead oxides are formed under
archaeological conditions where there is prolonged
atmospheric exposure.
• Physical cleaning. with soft brush & water, detergent, soap
removes the dirt.
• Chemical cleaning: The lead is immersed in 10%
hydrochloric acid, which will remove any adhering.
• Chemical cleaning: If lead dioxide is present, it can be
removed by soaking the object in 10% ammonium acetate.
• Chemical cleaning: If the objective is to completely
remove all of the lead corrosion products from a lead
object, a 5 percent solution of ethylenediaminetetraacacetic
acid (EDTA) disodium salt is effective.

49. Lead

50. Physical cleaning: with soft brush & water, detergent, soap removes the dirt.

51. If lead dioxide is present, it can be
removed by soaking the object in 10
percent ammonium acetate.
The lead is immersed in 10
percent hydrochloric acid,
which will remove any
adhering.

52. • If the objective is to completely remove all of the lead corrosion from a lead coin,
• A 5 % of ethylenediaminetetraacacetic acid (EDTA) disodium salt is most
effective.

53. Other 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 (200ml water, 20 gram
sodium chlorite)
• Using small equipments
• Glass crystal brush, Scalpels

54. Electrolytic Reduction

55. • Digital ultrasound cleaner is an electric device used to clean coins
by using the warm tap water and ultrasonic waves.
• Use this device to clean coins more professionally.
• Steps To Follow
Step 1: Switch on the machine and add the warm tap water or
copper cleaning solution for better results (UL901, Ultrasonic
Solution).
Step 2: Dump the coins into it.

56. Methods on 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.

57. Archaeological Findings

58. Socked them for few days in 10 per cent
solution of sodium sesqui-carbonate.
Or 5 per cent solution of Rochelle salt

59. Socked for few days in 10
% solution of sodium
sesqui-carbonate.
5 per cent solution of Rochelle salt

60. Coin Storage

61. Coin Storage

62. Coin
placement

63. Coin placement

64. Coins Display

66. Conclusion
• Prime duty of the museum
• Each items need different medicines
• Museum shall have in-situ laboratory
• Museums staff have at least have basic knowledge
regarding the preservation and conservation.
• Objects shall be inspected repeatedly.
• Before and after pictures are advised to see the
deterioration
• Conservations always done when its needed.
• Always conducted by the specialists.

67. Thank
You