FMF - Friends of Minerals Forum, discussion and message board

[bob kerr]

I thought I knew the answer to this question but after searching on the internet, I found that thumbnails:

- must fit inside a perky box (the diagonal of a perky box is about 1.4-1.5 inches - 3.6cm)
- no more than 1 inch (2.54cm) for the largest direction
- no more than 3cm for the largest direction

these are all significantly different - is there really a standard? how big is a "box-buster" - sometimes called a toenail? what box is it busting?

thanks,
bob

[rweaver]

[alfredo]

For your own collection, you're free to do whatever you like, but for competitive displays like those at the Tucson main show, there are rules, and the size rule is that a thumbnail has to fit inside a 1 inch (25.4 mm) cube. The judges have a 1 inch cube frame made out of wire to check in cases of doubt. A perfect pyrite cube 25 mm on an edge would count, but a long thin sulphosalt needle could be allowed even if it were almost 50 mm long, because it would fit in the cube diagonally. A standard Perky box measures slightly larger, about an inch and a quarter, but that doesn't count for competition rules.

[James Catmur]

To me those are compatible, it depends how you measure the 1" cube

Take a 1" cube (2.54cm) and it measures 1.41" (3.6 cm) on the base diagonal and 1.73" (4.4cm) on the diagonal from base corner to opposing top corner.

[rweaver]

[James Catmur]

I guess if you are not competing it is up to you to decide what a thumbnail is

[bob kerr]

I really don't have an issue with how my collection defines TN nor how a club's competitive rules define what a TN is - my question goes to selling and buying - dealers vary as to what they define as a TN and how they are grouped for sale - look these and others up yourself:

- Arkenstone - "Thumbnail specimens are usually no larger than one inch square and will generally fit into a 1.25” plastic perky box."
- John Betts and Taos Rockers - "Thumbnail-Sized Specimens 0.2-3cm"
- Mineral Mike - "These crystals/minerals will have a max dimension of 37mm."

just to name a few.

So, I have a nice pyromorphite single xl from Bunker Hill that is 3cm tall. In TGMS competition it is not a TN since the "as mounted" specimen (upright) will "bust the 1 inch box" BUT it's a TN by any other definition (even TGMS) as it will definitely fit inside either a 1 ich cube or a Perky cube if it is slanted.

Furthermore - terms like toenail, small miniature, large miniature, small cabinet and large cabinet have entered the vernacular.

To me the term TN and these other terms are meaningless - and all dealers should simply state the dimensions and refrain from using a title - and maybe competition cases should state simply that "to qualify, the largest dimension must be less than x cm".

bob