Buried Chinese Coins. — Rogers. 45 
is a definite order of succession. — The cuprite was formed first, 
then the malachite, then the azurite. Nearly all the specimens 
exhibit this paragenesis. 
Cuprite. — Cuprite usually occurs in small but distinct crys- 
tals. When the crystals with their brilliant reflecting surfaces 
are thickly scattered over the surface the coin makes a beautiful 
specimen. The dominant crystal forms are the cube and the 
octahedron. There are also the dodecahedron, a trapezohedron 
and a tetrahexahedron. On the best specimen the crystals pre- 
sent the following combination : cube, dodecahedron, octahe- 
dron and a trapezohedron. Several crystals were measured 
and the first three forms identified, but no indices could be as- 
signed to the trapezohedron. On other coins octahedral crys- 
tals occur. 
Malachite. — A mammillated structure with concentric lay- 
ers characterizes the malachite. It has been formed after the 
cuprite and before the azurite. 
Azurite. — Azurite does not occur as often or in as large 
amounts as malachite. It is often crystalline in structure, its 
drusy surface following the contour of the malachite, the 
formation of which preceded it. 
Copper. — Small, rough crystals of copper were observed 
on two of the coins associated with cuprite. 
Ceriissitc.- — Cerussite was found on nearly all the coins ex- 
amined. Though usually in subordinate amount, on one coin 
it was the dominant mineral. It is sometimes colored with 
cuprite. The lead probably came from some extraneous source 
as none could be detected in the coin itself. 
With the exception of the copper our occurrence is like that 
noted by Fletcher* on Roman coins from Chester. 
Appended is a list of minerals that have been found on 
coins with the names of observers, localities and references 
to publication. 
Azurite. — Lacroix — Algeria. Bull. soc. fr. Min. 6:175, 1883. 
Fletcher— Chester. Min. Mag., 7:187, 1887. 
Bornitc. — Daubree— Bourhoune les Bains. C. R. 80:461,1875. 
Gouvenain — Bourbon I'Archambault. C. R. 80:1297, 1875. 
Cerussite — Lacroix — Algeria, ibid. 
Fletcher — Chest.-r. ibid. 
* Loc. cit. 
