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Outlines of mineralogy

Chapter 21: AURUM, OR GOLD.
By Torbern Bergman
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About This Book

A concise scientific treatise that organizes fossil and inorganic substances by their constituent chemical components, advocating composition-based genera and species rather than superficial traits. It defines mineralogy, explains a natural system founded on prevalent parts and variations in mixture, and critiques reliance on color, hardness, and texture because these features often vary independently of composition. The work describes analytical approaches and difficult cases, offers supplemental genera in appendices, and supplies practical aids such as tables and an index to assist identification and application of mineral substances.

AURUM,
OR
GOLD.

§ 144.

The ſpecific gravity of this metal, when pure, is 19,640. Aqua regia diſſolves it; but except the dephlogiſticated muriatic acid, and in certain circumſtances the nitrous, no ſimple acid acts upon it, unleſs it has been previouſly calcined[56]. The quantity of phlogiſton neceſſarily taken away in the ſolution of 100 parts of gold, I eſtimate at about 394; whilſt the ſame quantity of ſilver, loſes by ſolution in the nitrous acid, 100[57]. Gold retains the phlogiſton neceſſary to its metallic form, more obſtinately than any other metal, except, perhaps, platina. It melts and calcines in the focus of a burning glaſs at 1301 degrees of heat.

§ 145.

AURUM nativum (gold native) united to ſilver.

Native.

I do not know that gold has ever yet been found perfectly pure.

AURUM nativum (gold native) united to copper.

Native.

AURUM nativum (gold native) united to ſilver and copper.

Native.

AURUM nativum (gold native) united to ſilver, copper, and iron.

Native.

AURUM (gold), mineralized by ſulphur, by means of iron.

Pyritical.

Cronstedt Min; § 166. a. Pyrites aureus.

But ſome doubt may be made about the mineralization of gold[58].

§ 150.

AURUM (gold) mineralized by ſulphur, together with ſilver, lead, and iron.

Minera aurifera Nagyayenſis.

I have not yet fully examined this[59].