Topaz Rough From Cambodia

Tako Province is south-east of Phnom Penh, not even one hundred miles. National Highway Two runs to the Vietnamese border-crossing south of Takeo Provincial Town at Phnom Denh. If you look at a satellite map of Takeo Province you can see where Route 2 crosses into Vietnam. Just before the crossing is a mountain west of the road reduced dramatically by quarried dirt, stone and clay 'stolen' for road projects; that is Denh Mountain. Just north of that is another mountain, same side of the road no name on the map, but home to Tonleab Village. Its interior is relatively unmarked by tree cutting or cropping. It is on this mountain that Topaz was discovered about ten years ago. Digging sites are a five kilometer climb into the interior of the mountain: an hour to an hour-and-a-half! Gem sellers sell cut gems at the base where the dirt road from town (Kampong Chrey) leads to a very nice recreational area with mountain streams, swimming hole -- with a moutain backdrop.

Above is a picture of four pieces of Topaz rough. The crystals are pitted from their journey to their final resting place, the mostly clay soil of the mountain. But Topaz is quite hard, measures at 8.0 on the Mohs scale, softer than Rubies or Sapphire (9.0) and diamond (10.0).

It is also one of those gemstones, like amethyst and citrine, or zircon, which are often found in large pieces without major inclusions. The crystal forms in Orthorhombic system. Geologists call its crystal habit 'prismatic'. The vast majority of the stones that are cut for sale are clear or have a light yellow or brown tint. There are stones being dug from the top of this mountain that are very light blue but the gem sellers at the base of the mountain are not certain whether it is blue topaz which they have cut and are selling. One lady whispered aquamarine to me. (We will pursue this question in another post :).

The stone above was photographed in early morning light, even though it is pitted it is translucent enough to glow with the rising sunlight that backit it.