Question

locating information in difficult graphics
approximate colors of jewelry alloys
gold (au)
red
yellow
green yellow
20 10 30 08 90 70 40 80 60 50 30 40 20 10 50 60 70 80 90
pale greenish yellow
yellowish
reddish
whitish
copper red
silver (ag) 10 20 30 40 50 60 70 80 90
copper (cu)
wt %cu
a jewelry maker uses different combinations of alloys to change the appearance of jewelry.
a piece of jewelry contains 30 percent gold, 10 percent silver, and 60 percent copper. what color is the jewelry?
○ reddish
○ copper red
○ yellow
○ yellowish
done
6 of 11

Explanation:

1. First, identify the percentages of each metal: gold (Au) is 30%, silver (Ag) is 10%, and copper (Cu) is 60%.
2. Then, refer to the ternary diagram (triangle graph) labeled "Approximate Colors of Jewelry Alloys". The axes represent the weight percentages of gold (top), silver (left - bottom), and copper (right - bottom).
3. Locate the point corresponding to 30% Au, 10% Ag, and 60% Cu on the graph.
4. Observe the color region that this point falls into. The region for these percentages (30% Au, 10% Ag, 60% Cu) is the "yellowish" region (checking the labels: the yellowish region is between the yellow and reddish regions, and with 60% Cu, 30% Au, and 10% Ag, it aligns with the yellowish area). The other options: "reddish" and "copper red" have higher copper and lower gold/silver (or different ratios), "yellow" has higher gold (e.g., the yellow region is around higher gold percentages like 70 - 90% Au? No, looking at the graph, the yellow region is near the gold vertex with lower copper. Wait, no, the graph's gold axis: the yellow region is at, say, 70 - 90% Au? Wait, no, the labels: the yellow region is near the gold (Au) vertex, with silver and copper percentages. Wait, the axes: the left axis is silver (Ag) from 0 - 90, bottom axis is copper (Cu) from 0 - 90, top axis is gold (Au) from 0 - 90. So for a point, the sum of Au + Ag + Cu should be 100% (since it's a ternary diagram for alloys, so the three components sum to 100%). So 30% Au, 10% Ag, 60% Cu: sum is 100. Now, looking at the color regions: the "yellowish" region is between the yellow (more gold, less copper) and reddish (more copper, less gold) regions. With 60% Cu, 30% Au, 10% Ag, this point is in the yellowish area (as per the diagram's color labels: yellowish is adjacent to yellow and reddish, and the percentages here match the yellowish region's composition). "Yellow" would have higher gold (e.g., 70 - 90% Au, lower copper), "reddish" and "copper red" have higher copper (e.g., 70 - 90% Cu, lower gold). So the correct color is yellowish.

Answer:

yellowish (the option corresponding to "yellowish" among the choices)