Does Moissanite Pass a Diamond Tester?

<h2>What does a diamond tester actually test?</h2>
<p>The tester you see at a pawn shop or jewelry counter is a thermal tester. It touches the stone with a heated tip and measures how quickly heat pulls away from it. Diamond pulls heat away faster than almost anything. The tester beeps when a stone moves heat fast enough to be a diamond.</p>
<p>It does not test for carbon. It does not test for "realness." It tests one physical property.</p>
<h2>Why does moissanite pass?</h2>
<p>Moissanite (silicon carbide) moves heat about as fast as diamond. On a thermal tester, the two read the same. That's not a trick. It's physics. The same property is why moissanite stays cool to the touch like diamond does.</p>
<h2>What fails the tester?</h2>
<ul>
<li>Cubic zirconia (CZ): fails. Moves heat slowly.</li>
<li>Glass and crystal: fail.</li>
<li>White sapphire: usually fails.</li>
<li>Lab diamond: passes, same as mined diamond.</li>
</ul>
<p>Most "iced out" jewelry sold online is CZ. That's why it fails at the shop.</p>
<h2>Can any tester tell moissanite from diamond?</h2>
<p>Yes. A dual tester (thermal plus electrical) can. Moissanite conducts a little electricity; diamond doesn't. Jewelers with a dual tester will flag moissanite. But the handheld pen tester most people own only checks heat, and moissanite passes that every time.</p>
<h2>Does the metal matter?</h2>
<p>Not for the tester. It only reads the stone. But the metal matters for everything else: brass under thin plating turns skin green, <a href="/blogs/moissanite-moe/will-925-sterling-silver-turn-your-skin-green">925 sterling silver doesn't</a>.</p>
<h2>FAQ</h2>
<h3>Does moissanite pass a diamond tester every time?</h3>
<p>On a thermal pen tester, yes. On a dual thermal-and-electrical tester, it reads as moissanite.</p>
<h3>Is moissanite fake?</h3>
<p>No. It's a lab-created gemstone made of silicon carbide, with its own hardness (9.25) and more fire than diamond.</p>
<h3>Can I test it myself?</h3>
<p>Yes. A basic pen tester costs about $15 online. Ours pass.</p>
<h3>Why does my chain fail the tester?</h3>
<p>It's almost certainly CZ or glass. Moissanite would pass.</p>