The World of Jewelry

Practical guides to choosing jewelry, materials and care — so you know what you are buying and how to wear it.

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Materials and qualityCeramic rings – pros, cons and how to chooseCeramic rings: how durable they are, whether they scratch and how to choose the right size. Black and white ceramic rings from ROTAS69.
Materials and qualityJewelry plating: gold, platinum and rhodiumHow gold, platinum and rhodium plating differ, what 14K, 18K and 24K mean on fashion jewelry, and which plating lasts longer.
Materials and qualityWhat does 585RG mean on fashion jewelry? A trick or a sign of quality?585RG is not a gold hallmark — on fashion jewelry it refers to a 585 (14K) gold color or plating, not solid gold. What it really means and how to judge quality.
Materials and qualityJewelry gone dark or leaving a green mark? What to doWhy fashion jewelry goes dark, why it can leave a green mark on your skin and when the plating really has worn off. Everyday care steps are on a separate page.
Materials and qualitySteel, silver or plating: what your jewelry is made ofWhat fashion jewelry is made of: medical steel, silver and gold plating. How they differ, which suits whom and how long each one lasts.
Materials and qualityThe benefits of medical steel jewelry for everyday wearWhy medical steel jewelry is made for everyday wear: it doesn't tarnish, copes with the shower and the gym, and doesn't irritate the skin. Jewelry from ROTAS69.
Materials and qualityMedical steel in jewelry: what it is and how to spot itMedical steel (316L) in jewelry: why it doesn't rust, is kind to skin and stands up to water – and how it differs from ordinary steel.
Materials and qualityCan you wear jewelry in water? Shower, pool and seaCan you wear fashion jewelry in the shower, the pool or the sea? What chlorine and salt water do to plating, and which pieces cope best with water.
Materials and qualityHypoallergenic earrings: style without compromise for sensitive skinWhy your ears react to earrings and which materials are safe: medical steel, titanium and rhodium plating. Hypoallergenic earrings from ROTAS69.
Materials and qualityGold-plated jewelry — what it can and can't doWhat gold-plated jewelry offers compared with solid gold, how long it holds its color and when it's a better choice than a precious metal.
Materials and qualityCubic zirconia: what it is and how it differs from diamondCubic zirconia in jewelry: what kind of stone it is, how it differs from diamond and how to care for it. Jewelry with cubic zirconia from ROTAS69.
Materials and qualityHow to care for gold-plated jewelry so the plating lastsHow to look after medical gold jewelry: why you mustn't polish it, what never to use, and where wear shows up first.

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Size guide

How to measure your finger

A

Measure a ring you already have

Take a ring that fits the finger you want to wear it on. Use a ruler to measure straight across the inside — that is the inner diameter in millimeters, and it is also the ROTAS69 size. Enter it in the calculator.

B

Measure your finger

Wrap a narrow strip of paper around the base of your finger (not over the knuckle). Mark where it overlaps, straighten it and measure the length in millimeters — that is the circumference.

Size chart

ROTAS69 Inner Ø	US	EU	UK	Circumference
14.5 mm	3.5	46	G	45.6 mm
14.9 mm	4	47	H	46.8 mm
15.3 mm	4.5	48	I	48.1 mm
15.7 mm	5	49	J	49.3 mm
16.1 mm	5.5	51	K	50.6 mm
16.5 mm	6	52	L	51.8 mm
16.9 mm	6.5	53	M	53.1 mm
17.3 mm	7	54	N	54.4 mm
17.7 mm	7.5	56	O	55.6 mm
18.1 mm	8	57	P	56.9 mm
18.5 mm	8.5	58	Q	58.1 mm
18.9 mm	9	59	R	59.4 mm
19.4 mm	9.5	61	S	60.9 mm
19.8 mm	10	62	T	62.2 mm
20.2 mm	10.5	63	U	63.5 mm
20.6 mm	11	65	V	64.7 mm
21.0 mm	11.5	66	W	66.0 mm
21.4 mm	12	67	X	67.2 mm
21.8 mm	12.5	68	Y	68.5 mm
22.2 mm	13	70	Z	69.7 mm
22.6 mm	13.5	71	Z+1	71.0 mm
23.0 mm	14	72	Z+2	72.3 mm
23.4 mm	14.5	74	Z+3	73.5 mm
23.8 mm	15	75	Z+4	74.8 mm

Full size chart — exact values. The ROTAS69 size is the inner diameter of the ring (Inner Ø) in millimeters. The EU size corresponds to the circumference; UK letters may differ by ±½ between jewelers.