MINERALOGY. 
SECT. CLXX. ’ 
2. Withfulphiir andarfenic, Argentum fulphure 
y arfenico mineralijatum. Miner a argenti 
ruhra^ The red or ruby-like fiiver ore. The 
Rothgulden oi the Germans. 
The colour of this ore varies as the pro- 
portion of each of thefe ingredients varies 
in the mixture •, viz. from dark grey to 
deep red : but when it is rubbed or 
pounded, it ahvays gives a red colour. 
When put in- the hre, it crackles and 
breaks and when the crackling ceafes, it 
melts eafily, the arfenic at the fame time 
exhaling in fmoke. 
a. Grey arfenical filver ore *, which is eitherji^ 
I . Plated, crufted, or leaved, and, 
2. Solid. 
h. The red arfenical filver ore. 
' ' I. Plated, cruiled, or leaved* 
‘ 2. Solid or fcaly, and, 
3. Crifcalliied. 
In this iafi: form it fhews the mofb 
beautiful red colour, and is often 
ferni-tranfparent. It contains about 
fixty per cent, in filver *, and- is found 
in thc’ greateft quantity at Andreaf-; 
berg in the Flartz. . 
SECT. CLXXL 
3. With fulphiirated arfenic and copper. Ar- 
gentum arfenico, & cupro fulphurato minera- 
lifaturn. Minera argenti alhi^ The JVeiJf- 
gulden of the Germans. 
This, in its folid form. Is of a light grey 
colour, and of a dull and fleel-grained tex« 
ture. 
