A one-of-a-kind necklace crafted from the exceptionally rare natural gemstone "Ruby in Quartz." This unique stone, formed only under limited geological conditions, features ruby and quartz crystallized together—a rarity in nature. From among them, we carefully selected a piece where the harmony between the two crystals is particularly striking. The softly toned, milky white quartz and the vivid yet subtly muted ruby lie side by side in a balance so exquisite, it appears almost intentionally composed—like a work of art. The ruby portion reveals natural variations in tone and visible inclusions, adding further character to this special gem. Set in a frame-like setting of 18K yellow gold reminiscent of a picture frame, it adds a refined touch of color to the neckline. Perfect not only as a graceful accent for everyday wear, ruby—also known as the birthstone of July—makes this necklace an ideal gift and a meaningful protective charm for someone born in that month.
【 Ryui Monthly piece 】
Gemstones shaped by time and chance No two are the same Our designers carefully select a "fragment" of nature every month Sharing with you the design and production process until it becomes jewelry —a special collection.
material：K18YG , Ruby in quartz
stone size：approx. 0.86ct
top size：approx. H9.1mm × W5.0mm × D3.7mm ( Including the jump ring )
length : approx.40cm ( adjuster 37cm )
We use Japanese sizes. For international equivalents, please refer to the correspondence table below.
Perimeter (mm)
Inner diameter (mm)
Japan (JCS)
EU (JIS / ISO)
US
UK
40.8
13
1
41
1
C
41.9
13.4
2
42
2
D
42.9
13.7
3
43
2.5
E
44
14
4
44
3
F
45
14.4
5
45
3.5
G
46.1
14.7
6
46
3.5 – 4
G – H
47.1
15
7
47
4 – 4.5
H – I
48.2
15.4
8
48
4.5 – 5
I – J
49.2
15.7
9
49
5
J
50.3
16
10
50
5.5
K
51.3
16.4
11
51
6
L
52.4
16.7
12
52
6.5
L – M
53.4
17
13
53
6.5 – 7
M – N
54.5
17.4
14
54
7 – 7.5
N – O
55.5
17.7
15
55
7.5 – 8
O – P
56.5
18
16
56
8
P
57.6
18.4
17
57
8.5
Q
58.6
18.7
18
58
9
R
59.7
19
19
59
9.5
S
60.7
19.4
20
60
10
T
61.8
19.7
21
61
10 –
T – U
62.8
20
22
62
10.5
UK
63.9
20.4
23
63
11
V
64.9
20.7
24
64
11.5
W
66
21
25
65
12
X
Resizing at the time of purchase
For rings over ¥33,000 (tax included)
We offer complimentary resizing within ±3 sizes from the size in stock. If you wish to have your ring resized, please proceed to the purchase screen of the item and enter the desired size in the remarks form in the shopping cart. Production period: about 4 weeks
For rings under ¥33,000 (tax included)
We do not accept resizing from stock items. Please contact us using the inquiry form and we will make a custom order in the desired size. Production period: about 5 weeks
Selecting your ring size
We recommend choosing a size that you can comfortably wear without feeling pressure or tightness when you make a fist, and without discomfort between adjacent fingers.
For wide rings of 6.0 mm or more
Compared to the number measured with a typical ring gauge, a wide width ring may feel a little tight to wear due to its large surface area. When considering a wide ring, we recommend that you choose a slightly looser size than you usually wear, 1 to 1.5 sizes up.
Please note that some rings cannot be resized due to their design.
Please check the details on each product page.
Contact
Please feel free to contact us using the form below.
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