Any thoughts on how to automatically identify a coin by type?

TopographicOceans

I want to be able to automatically categorize a coin by type.

I have a database with the attributes about each coin, and want to be able to assign the type of coin it is. I could use the PCGS Numbers, but I don't understand how they are assigned and I don't want to have to look it up for each coin.

The attributes I have about each coin include:

DenominationDateVariety

So I created a table with the following key

Demonization (6 digit whole number to hold 0.005 through 100.00 - or 000005 through 100000)Start Date (4 digit YYYY)End Date (4 digit YYYY)Variety (1 digit 0-9)

For example, a Capped But Quarter would have

Denomination = 0.25Date = 1818Variety = 1

So the key would have the same start/end date and be found in the range for that type coin.
000250/1818/1818/1

In the Type Set file I would have a records with
000250/1815/1828/1 = Capped Bust Variety 1 - Large Diameter
000250/1831/1838/2 = Capped Bust Variety 2 - Reduced Diameter, Motto Removed

So any 0.25 between 1815 and 1818 would be a Capped Bust Quarter, Variety 1 and between 1831 and 1838 would be a Capped Bust Quarter, Variety 2

For example, with the Quarters I can define still use the same structure since the date ranges
000250/1838/1853/1 = Liberty Seated Quarter Variety 1 - No Motto Above Eagle

A problem arises when the Mint issues a new type mid-year without any varieties with the same demonization.
Eagles would be defined as
010000/1866/1907/1 = Liberty Head, Motto Above Eagle
010000/1907/1908/1 = Indian Head, Variety 1 - No Motto on Reverse
010000/1908/1933/2 = Indian Head, Variety 2 - Motto on Reverse

A coin with the attributes

Denomination = 10.00Date = 1907Variety = 1

Would have a key of 010000/1907/1907/1 which falls into the same ranges both:
010000/1866/1907/1 = Liberty Head, Motto Above Eagle
010000/1907/1908/1 = Indian Head, Variety 1 - No Motto on Reverse

I can't think of an easy way to differentiate a Liberty vs. Indian Eagle of the same date.
All I can think of is adding a new attribute to the coin data base and adding it to the key in the Type Set category file, but then I have go and update each coin record to set it. I guess it's not that big of a deal since there are only a few coins that have a different major type design in the same year.

Any ideas?

BryceM

Ummmm, what was wrong with the PCGS numbers?

Sure, they're not entirely consistent, but it's pretty much the industry standard. They also accommodate varieties and eliminate ambiguity, which your system would not.

MsMorrisine

0.01
1909
problem

1.00
1921
problem

TopographicOceans

The problem with using the PCGS numbers is those identify a specific coin and I just want to know the type category.

For example, all quarters from 1999 to 2008 should map into "Washington 50 States Quarters" regardless of the state. And there are 100+ PCGS numbers for these that would have to be mapped out. Plus if my coin is raw or in a non-PCGS slab I have to go look it up.




<< <i>0.01
1909
problem

1.00
1921
problem >>


Yes - that's the problem - when the type changes for a denomination during the same year.

CoinZip

Is the database going to be a web site or just on your computer?

TopographicOceans

No it's just for me. I'm a type collector so I want to have the type defined for each coin, as well as generate a report so I can sell off duplicates.

I think I'll just have it pick the first match, and then I can edit it manually if I need too. I've probably only have a handful of coins that will be a problem.

CoinZip

add a filed called type

so your 09 Indian would be Indian Head in the type field and your 09 wheat would be Wheat Cent in the type field.

Query the type field and sort by year...?

yosclimber

At you stated, it can't be done automatically with just denomination and year, because there are often multiple types in a year.

Just code Variety directly as type (I would allow more than 9 values).
Then your type label table would just have Denomination, Variety and Type Label.

Examples:
5c types
Variety Type_Name
1 Half Disme (1792)
2 Flowing Hair - Small Eagle Half Dime
3 Draped Bust - Small Eagle Half Dime
4 Draped Bust - Heraldic Eagle Half Dime
5 Capped Bust Half Dime
6 Liberty Seated No Stars Half Dime
7 Liberty Seated Stars Half Dime
8 Liberty Seated added Drapery Half Dime
9 Liberty Seated with Arrows Half Dime
10 Liberty Seated Legend Obv Half Dime
11 Shield with Rays Nickel
12 Shield without Rays Nickel
13 Liberty no Cents Nickel
14 Liberty with Cents Nickel
15 Buffalo on Mound Nickel
16 Buffalo on recess Nickel
17 Jefferson Nickel
18 Jefferson War Silver Nickel
19 Jefferson low relief Nickel
20 Jefferson peace pipe nickel
21 Jefferson boat nickel
22 Jefferson buffalo nickel
etc.