You may have noticed that certain elements which were not included in the dataset, such as horncores, are not displayed. Other elements had very small sample sizes, so you might want to exclude them as well. One way of doing this is to use a definition query:
Bring up the elements layer's properties and choose the definition query tab.
If you are familiar with SQL you can simply type an expression into the box, equivalent to the WHERE clause in a select query. Otherwise, click the query builder button.
We want to exclude all elements with samples of fewer than 10. Double-click "Gomolava$.n" to add the 'n' field to the expression ('Gomolava$' indicates that the field is in the linked excel sheet rather than the attribute table), then type '>9' to complete it.
Click OK. The least well-represented elements should have disappeared.