January 18, 2022


A continuation of how a crystallized gold specimen was made. Hi it’s Dave again from Goldbay, in part 1 of this series I have explained the first process of how to prep a gold-bearing quartz into an exquisite crystallized gold specimen – which is checking of gold continuity inside the quartz. In this blog, I will explain to you the second process, thermal shock which is literally shocking the specimen to remove the bulk of the quartz. Also, below this blog is a video that demonstrates in full this second step in preparing gold quartz specimens.

The Thermal Shock Process In Removing Quartz Of Your Gold Specimen

Before going into details let’s recap on the first step of the whole process. In my previous video I demonstrated how to check the gold’s continuity using a device called continuity tester. And that is important because it gives us a pretty good idea of how the gold-bearing quartz will look after all the process is finished.

This time we will remove the bulk of quartz attached in our gold specimen using a process called thermal shock. In this process we will burn the quartz, heat the whole thing up to a red hot then dunk it in the water (that causes the sudden change in temperature) and then heat it up again until it breaks. Quartz breaks due the sudden variation in temperature that causes tension to the minerals. Since quartz are poor heat conductors it causes them to heat up or cool down in an uneven manner which in turn causes them to break or shatter its pieces.

Acetylene Torch

The device we will use to heat up the quartz is important. A large propane torch tool is often used to do the work. But because we want to selectively remove the quartz, we will instead use an acetylene torch with a small tip to concentrate a high heat on a certain area of the specimen. I highly recommend using a safety glass to protect your eyes from the pieces of quartz popping out when it breaks.

Important Tips When Doing The Thermal Shock Process

Use An Oxidizing Flames

  • Control the flame from your acetylene torch into a point of an oxidizing flame. If you are not familiar with various burners and how to control your flames, check the image below for comparison. The number 4 – a flame shorter than the others, the color darkens, and produces a sound that hisses and roars is an exact example of an oxidizing flame. These features are results of an excessive amount of oxygen released from your burner. Once golds are close to popping out of the quartz, you can use a more aggressive flame to heat the remaining quartz until its removal.

Heating Up The Gold It Self

You can heat the gold that is close to the quartz but be careful not to melt the gold. The gold melting point is around 1,064 Celsius or 1947.2 Fahrenheit. You can watch my part 2 video below as I fully explain how it works.

Using Air Scriber – Part 3 Of Prepping Gold Quartz Specimen Series

In the next blog, I will be chipping the remaining quartz using a tool called air scriber. It’s a longer process compared to thermal shock but what it does is it specifically removes the quartz that are closely attached to our gold.  In my next video blog part 3 of this series, I will be demonstrating the entire air chipping process. 

In the video below, I will show you how I remove a bulk of quartz using the thermal shock process.

About the Author

I started Goldbay in 1999 as a response to man-made or fake gold nuggets being auctioned on Ebay. I wanted a site that could control the authenticity of products and connect gold nugget buyers with a reputable source

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