GB2441592A

GB2441592A - Coin grading

Info

Publication number: GB2441592A
Application number: GB0617656A
Authority: GB
Inventors: Stephen Lockett
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-09-08
Filing date: 2006-09-08
Publication date: 2008-03-12
Also published as: GB0617656D0; GB2441592A8

Abstract

In a first step of the method for coin grading, an overall impression of a coin is judged against a predetermined set of benchmark coins establishing broad grading bands with respective numerical values A for the bottom of each said band, the highest value of A for the highest band being less than the value B that would be attributed to an absolutely perfect proof coin. In a second step, which may be only applied to coins falling in the highest band, at least one of the following attributes of the coin is judged, namely: (i) striking (including die wear and die rust), (ii) lustre, (iii) contact marks, (iv) hairline scratches and cabinet friction, (v) haymarking and (vi) adjustment lines, against a predetermined set of benchmark coins for that attribute showing different degrees or extents of that attribute, to provide for the candidate coin a figure C, for the degree or extent of that attribute. A final grading figure D = B G ECn is established, where ECn is the sum of the values of Cn for said at least one attributes for the coin.

Description

COIN GRADING

This invention relates to numismatic coin grading.

The conventional practice for grading coins by dealers in coins is largely subjective and dependent upon the experience of the grader. Although terms such as uncirculated, perfect and proof, excellent are widely employed by coin dealers, different graders may classify the same coin in different ways. There is no absolute accepted standard for coin grading so that each dealer in coins or purchaser of coins must examine individual coins and form their own view as to the grade of an individual coin.

The example of my system described in detail hereinbelow is designed, so far as possible, to reduce subjectivity to a minimum and to generate a grading, preferably on a scale between 1 and 100 that, for an individual coin, is likely to be widely accepted by different graders using the system.

As will become clear from the detailed description below, the system relies upon established benchmark coins. Comparison of a candidate coin to be graded with the benchmarks will enable a grader, without too much trouble, to say whether the candidate coin is better or worse than a predetermined benchmark coin. It follows that once initial sets of benchmark coins have been established, further sets of benchmark coins can readily be established which substantially correspond to the original benchmark set.

In accordance with a first aspect of the present invention, there is provided a method of grading coins, the method comprising a first step in which an overall impression of a candidate coin is judged against a predetermined set of benchmark coins establishing broad grading bands with respective numerical values A for the bottom of each said band, the highest value of A for the highest band being less than the value B that would be attributed to an absolutely perfect proof coin, to establish in which broad grading band a candidate coin falls; and a second step applied to candidate coins falling in the highest band, and comprising judging at least one of the following attributes of the candidate coin, namely: (I) striking (including die wear and die rust), (ii) lustre, (iii) contact marks, (iv) hairline scratches and cabinet friction, (v) haymarking and (vi) adjustment lines, against a predetermined set of benchmark coins for that attribute showing different degrees or extents of that attribute, to provide for the candidate coin a figure C for the degree or extent of that attribute; and deriving a final grading figure D = B - where EC is the sum of the values of C for said at least one attributes for the candidate coin.

Preferably all six of the attributes (1) to (vi) are taken into account, although it would be possible to provide a grading system, albeit less satisfactory, in accordance with the present teachings, that employed fewer than all of these attributes. Accordingly, there are preferably six sets of predetermined benchmark coins for the respective attributes (i) to (vi).

For candidate coins that are judged not to fall within the highest band in the first step, an alternative second step may be applied, the alternative second step comprising judging at least one of the following attributes of the candidate coin, namely: (a) wear of the candidate coin, (b) tone and evenness of wear of the candidate coin and (c) one or more problems of the candidate coin selected from marks or knocks to the edge or surface, stains or discolouration, porosity of the fields (corrosion which has altered the appearance of the field) and scratches, against a predetermined set of benchmark coins for that attribute showing different degrees or extents of that attribute and with each of which a predetermined value E for that attribute is associated, values for E increasing with quality; and deriving a final grading figure D = A + where A is the numerical value of the grading figure attributed to the bottom of the broad grading band established for the candidate corn in the first step, and E1 is the sum of the values of E for said at least one attributes for the candidate coin, the maximum possible value for being no more than the increment in A from one broad band to another.

Accordingly, in a second and alternative aspect of the present invention, there is provided a method of grading coins, the method comprising a first step in which an overall impression of a candidate coin is judged against a predetermined set of benchmark coins establishing broad grading bands with respective numerical values A for the bottom of each said band, the highest value of A for the highest band being less than the value B that would be attributed to an absolutely perfect proof coin, to establish in which broad grading band a candidate coin falls; and, for a candidate coin not falling in the highest band, a second step comprising judging at least one of the following factors of the candidate coin, namely: (a) wear of the candidate coin, (b) tone and evenness of wear of the candidate coin and (c) one or more problems of the candidate coin selected from marks or knocks to the edge or surface, stains or discolouration, porosity of the fields (corrosion which has altered the appearance of the field) and scratches, against a predetermined set of benchmark coins for that factor showing different degrees or extents of that factor and with each of which a predetermined value E for that factor is associated, values for E increasing with quality; and deriving a final grading figure D = A + where A is the numerical value of the grading figure attributed to the bottom of the broad grading band established for the candidate coin in the first step, and EE is the sum of the values of E for said at least one factors for the candidate coin, the maximum possible value for being no more than the increment in A from one broad band to another.

Preferably the second step takes account of all three factors (a), (b) and (c).

However, although believed less satisfactory, a grading system in accordance with the present teachings could employ less than all of the three factors.

In a third alternative aspect of the present invention, there is provided a grading set of benchmark coins for carrying out a grading of a candidate coin, the grading set comprising a first set of benchmark coins adapted to provide an overall impression establishing broad grading bands; and, for at least one attribute selected from (i) different qualities of striking, (ii) different extents of lustre, (iii) different extents of contact marks, (iv) different extents of hairline scratches and cabinet friction, (v) different extents of haymarking and (vi) different extents of adjustment lines, a respective second set of benchmark coins showing said different extents.

Preferably the grading set includes one or more further sets of benchmark coins adapted for grading lower grade coins by at least one of (a) extent of wear, (b) tone and evenness of wear and (c) problems or faults selected from marks or knocks to the edge or surface, stains or discolouration, porosity of the fields (corrosion which has altered the appearance of a field) and scratches.

The invention is hereinafter more particularly described by way of example only.

Whereas the grading of an individual candidate coin heretofore has often been subjective with different experts taking differing expert views, it is in general far easier to say which of two candidate coins is the better in respect of a particular quality. The system described in detail hereinbelow makes use of this observation and, in so doing, establishes gradings for individual coins which are likely to be reproduceable when the grading is carried out by different experts, so enabling gradings to be established for particular coins that are likely to attract widespread acceptability.

The system is designed for grading genuine original coins only, and is inappropriate for grading coins that are forgeries, or coins that have been tooled to improve their appearance or to conceal damage.

In general the obverse side of the coin is the side to be graded unless the reverse is plainly inferior, in which case the reverse should be graded instead.

The preferred grading system is divided into two stages.

In the first stage a candidate coin is attributed to broad grading bands by comparison with a set of benchmark coins to which respective numerical values A are attributed for the bottom end of each said band.

Preferably the grading is designed to produce a grading measurement of between 1 and 100 in which 100 represents an absolutely perfect proof coin.

Preferred broad bands represent the respective ranges 1 to 19, 20 to 39, 40 to 59, 60 to 79 and 80 and above. For the finest band (that is coins likely to have a grading of or above), a more detailed second grading step is carried out as compared with the second stage steps for coins with lower grading bands, as described below.

Thus, for coins in the highest grading band, an assessment is first made in relation to striking (which includes die wear and die rust). A set of benchmark coins with different qualities of striking is provided. It is not necessary to provide a benchmark coin for each value of striking quality as interpolations (in other words slightly better or slightly worse than a particular benchmark) may be attributed for qualities of strike between those of individual benchmark coins. Preferred attributed marks Fl are according to the table set out below.

Definition Quality of Strike Mark Perfect and proof Perfect 0 Excellent Proof-like or Proof not perfect I Excellent Proof-like or Proof not perfect 2 Excellent Non Proof as good as they come 3 Very Good Non Proof excellent 4 Very Good Non Proof very good 5 Very Good Very high points show signs of weakness 6 Good High points show signs of weakness 7 Good Some minimal weakness 8 Good Very small weak areas 9 Good A few small weak areas 10 Below Average Larger weak areas 11 Below Average Some noticeable weak areas 12 Below Average More noticeable weak areas 13 Below Average More noticeable weak areas 14 Weak 5% weak areas 15 Weak 6-7% weak areas 16 Weak 8-9% weak areas 17 Weak 10% weak areas 18 Very Weak, Bad 12-15% weak areas 19 Very Weak, Bad 15-20% weak areas 20 Very Bad Over 20% weak areas More than 20 The second attribute for the finest broad grading band is lustre. Preferably this is measured in different ways depending upon the metallic constitution of the coin.

For copper, bronze, brass and cupro-nickel coins the extent to which a candidate coin retains its original mint lustre is assessed by reference to benchmark coins, preferably according to the table set out below.

Lustre Remaining Marks 100% 0 95% 1 90% 2 85% 3 80% 4 75% 5 70% 6 65% 7 60% 8 55% 9 50% 10 45% 11 40% 12 35% 13 30% 14 25% 15 20% 16 15% 17 10% 18 5% 19 0% 20 Additional benchmark examples are preferably provided so that additional marks may be added for unevenness of lustre, for spots or for discolouration.

In the case of silver coins a different approach is adopted.

Again, using a set of previously determined benchmark coins with different degrees of retention of original mint lustre, a mark is attributed to a candidate coin, preferably by adoption of the table set out below.

Perfect as struck lustre 0 Beautiful Original Brilliance 1-3 Lovely tone or nice brilliance 4-6 Well balanced Eye catching 7-10 tone Uneven but not unpleasant 11-14 Uneven 15-17 Unattractive, dull, dipped 18-20 Ugly -Terrible 20-25 I Terrible Tarnished I Above 25 I It should be noted that the term "dipped" applies to a silver coin that has been dipped in a solution to remove toning caused by oxidation and thereby to restore its original mint brilliance appearance. Such coins can look very similar to an original example with its full mint lustre. Since the dipping process is non-abrasive, and some collectors take the view that it causes no long-term damage to the coin and allows marks and scratches to be revealed that were otherwise difficult to observe when the coin was toned, dipped coins are included in the present grading system but, of course, a dipped coin exhibiting lustre is not the same as a coin with its original lustre and should not attract a grading corresponding to that of the original coin. It is nonetheless included in the present grading system.

In the case of gold coins, a similar set of benchmark coins retaining different extents of the original mint lustre are provided for judging the candidate coin thereagainst and a mark is attributed to the extent of remaining lustre, preferably generally according to the table set out below.

Perfect as struck lustre 0 Beautiful Original Brilliance 1-3 Nice Brilliance 4-6 Less Brilliance 7-10 Subdued Brilliance 11-14 Duller Brilliance 15-17 Dull 18-20 Ugly, Tarnished 20-2 5 Accordingly a mark F2 is established for the candidate coin for lustre.

The third attribute which is assessed for coins falling in the highest broad grading band is that of contact marks.

Again, a benchmark collection of coins is provided with different extents of contact marks and a mark F3 of between 1 and 60 is allotted to the extent of contact marks on the candidate coin, the scale being adjusted so that coins which score higher than 60 will be coins that would have a final grading of below 80 and so The fourth attribute to be assessed is that of hairline scratches and cabinet friction. A benchmark collection of coins is again provided allowing a mark F4 to be established indicating the extent of hairline scratches and cabinet friction, preferably on a scale of 1 to 60 where a score of 60 or more would indicate a final grading of below 80.

The fifth attribute to be measured is that of haymarking.

Coins prior to the reign of George HI can show surface faults which appear as small dark flecks or pits that are termed "hay marks". Accordingly, a set of benchmark coins with different extents of haymarking are provided for visual comparison of a candidate coin with the benchmark set to establish a value F5 for haymarking, preferably according to the table set out below.

None 0 Very Few 1-3 A few 4-6 Several 7-10 Moderate 11-14 Plenty 15-17 Lots 18-20 Very Heavy 20-25 Above 25 Generally prior to the reign of George III, coins were weighed at the time of their minting, and any coin deemed over-weight would have had the weight reduced by running a file across the surface to scrape away a small amount of the metal. The resulting scratches are termed "adjustment lines".

Accordingly, a set of benchmark coins is provided with different extents of adjustment lines for visual comparison of a candidate coin with the benchmark set to establish a value F6 for adjustment lines, preferably according to the table set out below.

None 0 Very Few 1-3 A few 4-6 Several 7-10 Moderate 11-14 Plenty 15-17 Lots 18-20 Very Heavy 20-25 Atrocious Above 25 From these six assessments, an overall grading figure of between 80-100 is assessed from the following equation: B = 100 -(F1+F2+F3+F4+F5+F6) /3.

For coins which are judged in the first step as not falling within the highest of the broad grading bands, a different assessment is more appropriate in order to establish a final grading, preferably in the range of! to 80. There may also be coins, initially thought to fall in the top broad grading band, for which the grading B resulting from the above described grading steps works out to be under 80, so that it may have been incorrect to include such coins in the top band initially. For such coins the different grading assessment described below should be applied, placing such coins in the next lower broad grading band.

A first benchmark set of coins with different extent of wear is established for visual comparison between a candidate coin and the benchmark set in order to attribute a mark Gi for wear, preferably according to the table set out below.

Excellent for grade 18-20 Better than average for this grade 14-17 Consistent with this grade 10-13 Below average for this grade 7-9 Poor for this grade 4-6 Bad for this grade 0-3 A second assessment is made for tone and evenness of wear. Coins may wear evenly or unevenly and coins also develop toning due to the reaction of the metal of the coin with air and any foreign bodies with which it may have been in contact. The toning may also be even or uneven. The tone and evenness of wear is established by employing a benchmark set of coins with different extent of tone and evenness of wear and visual comparison between a candidate coin and the benchmark set to attribute a figure G2 for tone preferably on the scale set out in the

table below.

Excellent for grade 18-20 Better than average for this grade 14-17 Consistent with this grade 10-13 Below average for this grade 7-9 Poor for this grade 4-6 Bad for this grade 0-3 A third assessment is made for coins falling other than in the highest band according to additional problems or faults which they may possess, selected from marks or knocks to the edge or surface, stains or discolouration, scratches and porosity of the fields. Porosity consists of corrosion which has altered the appearance of a field of the coin from what would normally be seen. Again, benchmark sets of coins are established with different extents of problems or faults, to which numerical values are attributed, preferably according to the table set out below.

Minimal 18-20 Less than average for this grade 14-17 Consistent with this grade 10-13 More than average for this grade 7-9 A lot for this grade 4-6 Maximum for this grade 0-3 A visual assessment of the candidate coin against the benchmark set of coins is made in order to establish a figure G3 for problems for the candidate coin.

Finally, an overall grading H is made for coins in the broad grading bands other than the top such band according to the following equation H = A +(G1+G2+G3)/30, where A is the bottom grading value for a particular broad grading band as established in the first step using the first set of benchmark coins.

Claims

Claims 1. A method of grading coins, the method comprising a first step

in which an overall impression of a candidate coin is judged against a predetermined set of benchmark coins establishing broad grading bands with respective numerical values A for the bottom of each said band, the highest value of A for the highest band being less than the value B that would be attributed to an absolutely perfect proof coin, to establish in which broad grading band a candidate coin falls; and a second step applied to candidate coins!lling in the highest band, and comprising judging at least one of the following attributes of the candidate coin, namely: (i) striking (including die wear and die rust), (ii) lustre, (lii) contact marks, (iv) hairline scratches and cabinet friction, (v) haymarking and (vi) adjustment lines, against a predetermined set of benchmark coins for that attribute showing different degrees or extents of that attribute, to provide for the candidate coin a figure C for the degree or extent of that attribute; and deriving a final grading figure D = B - where is the sum of the values of C for said at least one attributes for the candidate coin.
2. A method according to Claim 1, wherein the second step applied to candidate coins falling in the highest band comprises judging all six of the attributes (i) to (vi) for the candidate coin, there being respective sets of predetermined benchmark coins for the respective attributes (i) to (vi).
3. A method according to Claim 1 or Claim 2, wherein (ii) lustre is differently judged for copper, bronze, brass, and cupro-nickel coins, for silver coins, and for gold coins, respective lustre benchmark sets of copper, bronze, brass, and cupro-nickel coins, of silver coins, and of gold coins being provided. **.*
4. A method according to Claim 1 comprising an alternative second step for candidate coins that are judged not to fall within the highest band in the first step, * the alternative second step comprising judging at least one of the following *** attributes of the candidate coin, namely: (a) wear of the candidate coin, (b) tone and evenness of wear of the candidate coin and (c) one or more problems of the candidate coin selected from marks or knocks to the edge or surfbce, stains or discolouration, porosity of the fields (corrosion which has altered the appearance of the field) and scratches, against a predetermined set of benchmark coins for that attribute showing different degrees or extents of that attribute and with each of which a predetermined value E for that attribute is associated, values for E increasing with quality; and deriving a final grading figure D = A + where A is the numerical value of the grading figure attributed to the bottom of the broad grading band established for the candidate coin in the first step, and EE is the sum of the values of F for said at least one attributes for the candidate coin, the maximum possible value for being no more than the increment in A from one broad band to another.
5. A method of grading coins, the method comprising a first step in which an overall impression of a candidate coin is judged against a predetermined set of benchmark coins establishing broad grading bands with respective numerical values A for the bottom of each said band, the highest value of A for the highest band being less than the value B that would be attributed to an absolutely perfect proof coin, to establish in which broad grading band a candidate coin falls; and, for a candidate coin not IWling in the highest band, a second step comprising judging at least one of the following factors of the candidate coin, namely: (a) wear of the candidate coin, (b) tone and evenness of wear of the candidate coin and (c) one or more problems of the candidate coin selected from marks or knocks to the edge or surface, stains or discolouration, porosity of the fields (corrosion which has altered the appearance of the field) and scratches, against a predetermined set of benchmark coins for that factor showing different degrees or extents of that factor and with each of which a predetennined value E for that factor is associated, values for E increasing with quality; and deriving a final grading figure D A + EEC, where A is the numerical *::::* value of the grading figure attributed to the bottom of the broad grading band established fbr the candidate coin in the first step, and EE is the sum of the values * . * of E1, for said at least one factors for the candidate coin, the maximum possible value for EE being no more than the increment in A from one broad band to another. *..S * . S...

*:
6. A method according to Claim 4 or Claim 5, wherein the second step applied to candidate coins not falling in the highest band comprises judging all three of the factors (a), (b) and (c), there being respective sets of predetermined benchmark coins for the respective factors (a), (b) and (c).
7. A grading set of benchmark coins for carrying out a grading of a candidate coin, the grading set comprising a first set of benchmark coins adapted to provide an overall impression establishing broad grading bands; and, for at least one attribute selected from (i) different qualities of striking, (ii) different extents of lustre, (iii) different extents of contact marks, (iv) different extents of hairline scratches and cabinet friction, (v) different extents of haymarking and (vi) different extents of adjustment lines, a respective second set of benchmark coins showing said different extents.
8. A grading set according to Claim 7, further comprising respective lustre benchmark sets for copper, bronze, brass, and cupro-nickel coins, for silver coins, and for gold coins.
9. A grading set according to Claim 7 or Claim 8, comprising one or more further sets of benchmark coins adapted for grading lower grade coins by at least one of (a) extent of wear, (b) tone and evenness of wear and (c) problems or faults selected from marks or knocks to the edge or surfuce, stains or discolouration, porosity of the fields (corrosion which has altered the appearance of a field) and scratches.
10. A method of grading coins substantially as hereinbefore described.
11. A grading set of benchmark coins for carrying out a grading of a candidate *::::* coin, the grading set being substantially as hereinbefore described. S.. * ** ** * 0*sS * S **SS 55*5* * S