• Close view of a square tabular crystal of hydroxyapophyllite, on bunchy off-white druzy. The crystal tilted so light reflects off the main square face, highlighting the small round spots speckling its surface. They coat the top and right edges abut are more dispersed on the main face.
  • Detail of the gradient of small brown lizardite crystals covering the hydroxyapophyllite, densest on the far corner and fading to fewer at the near corner
  • The piece has decent translucency but is a bit dark due to the lizardite coating.
  • The specimen is on styrofoam in a thumbnail box, black plastic base and clear top tilted open.
  • The back of the specimen, coated with bumpy brown lizardite. The piece has been mounted on styrofoam using tack.
  • The specimen with the thumbnail box closed
  • The thumbnail box held in a hand to show scale, in indirect sunlight.
  • Scale image of the piece on a measuring mat. The thumbnail box is one and a quarter inches, with the specimen measuring less than half and inch with the crystal about a centimeter.
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Hydroxyapophyllite thumbnail

Hydroxyapophyllite thumbnail

$9.00 USD
$9.00 USD
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Locale: N'Chwaning II Mine, South Africa

Approx dimensions: 8mm crystal; 1.25" thumbnail box

 

This thumbnail specimen features a single hydroxyapophyllite crystal with lizardite and calcite on matrix. Properly called "hydroxyapophyllite-(K)," hydroxyapophyllite is a variety of apophyllite that is typically colorless to semi-translucent white with inclusions. It more frequently grows cubic crystals, but these specimens from the renowned N'Chwaning Mines region form square tabular crystals similar to wulfenite.

The hydroxyapophyllite crystal is a well-formed tabular square measuring 8mm. The matte brown mineral coating the specimen is lizardite, which often grows in small spots along the junctions of the hydroxyapophyllite crystal. In this case it forms a nice gradient across the surface. The crystal is attached to a piece of matrix coated in calcite druzy.

UV reactivity Some calcite fluoresces and phosphoresces weak red under 365 nm UV light. It can cause the hydroxyapophyllite crystals growing over it to glow a weak red—try it in a dark room with a strong flashlight.

** Brittle warning! Hydroxyapophyllite specimens are somewhat delicate and may shed pieces. Use care if you remove the specimen from the thumbnail box. The specimen is mounted with tack. If small amounts stick to the mineral, just ball up the tack and press it onto the spots a few times until they stick to the ball.

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