1. The Evils that beset mineral collections: Time

How many ways can time damage a mineral collection?
The primary problem is in the retention of information, but minerals themselves can also be damaged.

How can information be lost?

• If you haven't written something down, it can be forgotten. That includes the location of samples and information. Take the time to label your specimens, even if with temporary labels, as you acquire them.
• Sometimes notes (especially receipts) are not prepared using archival materials. Paper crumbles, ink fades, tape becomes unsticky. Try to avoid using non-archival materials; make copies of unstable notes.
• Computer programs become obsolete over time; computer media may not be stable (e.g., many CDs are only rated for 10 years), or their related hardware may become obsolete. (For instance, my Ph.D. thesis is on large-format magnetic tape, and prior to that I used punch cards to index collection information: these are now dead media.) If your information is archived on hard media, update the media regularly, and check that the information has not become corrupted in the meantime; if it is in "the cloud," still make your own backups.
  
• When the time comes to pass your collection along to another place, will you be there to handle the transfer? Or will your heirs know where the specimens are, which have special care issues, which label belongs to each specimen, and who gets what? Collections deserve special attention in the estate planning process. (And does the recipient know the collection is coming? Give your heirs a chance to prepare for the collection's arrival.)
  

What can happen to minerals?

• Over time, minerals can react with their environment. Sharp water soluble crystals can become rounded due to humidity changes over time; some pyrite and marcasite crumble due to bacterial contamination; acid paper reacts with sulfide minerals.
  
• Metastable minerals can revert or decompose: for instance, hydrous (or "hydratable") minerals gain or lose water.
  

Some of these changes can be mitigated with a stable environment and isolation of some specimens; but some is inevitable.