Compare the catalogue

One row is one vial, not one compound. A certificate is issued against a lot, and a lot is a particular strength of a particular compound. Each of the compounds here that carries a published report also sells a strength that does not, so a table with one row per compound would put a tick beside a vial no laboratory has examined. Sorting by the certificate column shows you exactly which vials have been reported on.

Price per milligram is arithmetic, not a claim. It is the listed price divided by the mass printed on the label, computed here rather than written down anywhere. Where the cell reads n/a no honest figure exists: a solution is sold by volume and its label states millilitres rather than a mass, and a blend covers more than one compound in a ratio the catalogue does not publish — so dividing its combined mass would produce a number that compares against nothing else in the column. Those rows sort to the bottom in both directions rather than being treated as cheap or as dear.

The certificate column is not a purity ranking. No measured result appears in this table, and that is deliberate. A result belongs to the lot it was measured on; lining three of them up beside compounds that have never been tested would invite a comparison the data does not support. The column tells you whether a report exists and links to it, and the report states its own figure, its margin of error and the date it was issued.

A green marker means the report carries an identity row confirming the compound against a reference standard. A grey one means the report was read and carries no such row — it reports purity and quantity only. That distinction is taken from a record of what a person actually saw on each scan, not assumed from the fact that a certificate exists.