slowly but surely.

*looks around*

I mean it kinda depends on where you stick it because malachite does not like acidic environments very much and the malachite will degrade and also might dye your bits blue-green as the copper dissolves out.

Oh my god guys it’s poisonous

I… no… I think you’re thinking of pure sodium?

I’m looking into it.

UPDATE:

Today in “I’m so sorry, coworkers, it’s for Tumblr,” I brought this post to the attention the science reporters at BuzzFeed. Dan Vergano did a some research and weighed in on the question “Can you use malachite as a dildo or is it toxic?”

*biologist crashes through the underbrush* Ok so here’s the thing though Malachite is not poisonous to YOU. BUT fucking this stalactite will probably wreck your vaginal flora and leave you with a gruesome infection within a couple days. Want details? SO GLAD YOU ASKED, ‘CAUSE HERE THEY ARE. • Malachite is not copper oxide. It’s Cu2CO3(OH)2. Like most carbonates it’s water soluble– that’s how it became a stalactite in the first place! And technically any given chunk of “malachite” isn’t just malachite– it’s a mix of various copper carbonates & oxides. This will become important later.  • When malachite dissolves it makes a bunch of copper (Cu++) ions. Cu++ is GREAT at killing bacteria and fungi– so good at it that sprays with Cu++ get used a lot as a spray in agriculture to stop plant disease. It takes such a large dose to harm larger organisms that copper sprays are used a lot in organic agriculture (like Bordeaux mixture).  So bottom line, yes malachite is technically nontoxic to humans. But it kills bacteria when it dissolves and releases Cu++. • Malachite dissolves somewhat slowly in water– but vaginal secretions aren’t just any water. A healthy human vagina has a pH of 3.8-4.5 and a salinity of about 0.9%. It’s also warmer than your average underground cave at 37°C (or 98.5°F in American meat units). As luck would have it, acidity, salinity, and warmth all make malachite dissolve faster.  • In other words, the human vagina dissolves malachite.  • I have no deeper explanation for why human females can dissolve rocks with our genitals. It simply is.  • Gonna to take a quick moment to point out that sex toys that dissolve when you use them are maybe not the best investment.  • Anyway the key question now is “how fast does the human vagina dissolve malachite?” Are we talking geological timescale, a Nazis-in-Indiana-Jones situation, or something in between? If the reaction kinetics of dissolution are very slow, then there’s nothing to worry about. An encounter with a stalactite would have to last years for enough Cu++ to leach out to cause problems. If it’s quick then we’re in trouble.  • Unfortunately it looks like nobody really knows. One of the best sources on how malachite dissolves & precipitates in water– an EPA document on how to avoid too much Cu++ in municipal drinking water systems– helpfully says “The kinetic constraints on the formation of these solids in water systems are largely unexplored” (p. 42) because end equilibrium points is all you need to run a city water system safely. In other words, the experiments that would tell us how fast malachite dissolves in various types of water just don’t exist because nobody’s ever needed to know before. So we’d better assume it’s going to happen reasonably quickly, #for safety. • So in best scientific fashion, we’re just going to bullshit our way ahead using what facts we DO have on hand: endpoint equlibria.  • Is there any info out there telling us what equilibrium concentration of Cu++ we get in salty acidic water at body temperature? Almost! One J.F. Scaife published some great data on this back in 1957. TAKE IT AWAY, SCAIFE. 

friends, lemme share this little gem with you