Sapphire ring: where to get it

Source	Quantity	Chance per roll
Angry barbarian spirit []	1	2/123
Berserk barbarian spirit []	1	2/123
Bird's nest (ring) []	1	40/100
Bird's nest+ (ring) []	1	1,423/7,058
Bronze key black []	1	Rare
Bronze key brown []	1	Rare
Bronze key crimson []	1	Rare
Bronze key purple []	1	Rare
Bronze key red []	1	Rare
Crawling hand []	1	2/128
Enraged barbarian spirit []	1	2/123
Giant skeleton []	1	2/128
Jungle horror []	1	7/128
Magpie [{'content': 'Estimated rarity may be inaccurate due to a low sample size.', 'name': 'inaccurate'}]	1	78/854
Menaphite gift offering (large) []	1	33/800, 4 rolls
Menaphite gift offering (large) (Ironman Mode) []	1	33/800, 4 rolls
Menaphite gift offering (medium) []	1	33/800, 3 rolls
Menaphite gift offering (medium) (Ironman Mode) []	1	33/800, 3 rolls
Menaphite gift offering (small) []	1	33/800, 2 rolls
Menaphite gift offering (small) (Ironman Mode) []	1	33/800, 2 rolls
Mummy (Jaldraocht Pyramid) []	1	10/513
Mummy []	1	10/513
Mummy (Ullek) []	1	10/513
Sarcophagus (Jaldraocht Pyramid) []	1	Rare
Simple Chest [{'content': 'Estimated rarity may be inaccurate due to a low sample size.', 'name': 'inaccurate'}]	1	20/376
Skeleton (Tarn's Lair) (High level) []	1	2/128
Skeleton brute []	1	2/123
Skeleton heavy []	1	2/123
Skeleton hero []	1	2/123
Skeleton thug []	1	2/123
Skeleton warlord []	1	2/123
Small chest [{'content': 'All items in the above table drop together at once.', 'name': 'p1'}]	1	2/150
Small chest [{'content': 'All items in the above table drop together at once.', 'name': 'p6'}]	1	6/150
Small chest [{'content': 'All items in the above table drop together at once.', 'name': 'p12'}]	1	5/150
Small chest [{'content': 'All items in the above table drop together at once.', 'name': 'p17'}]	1	3/150
Small chest [{'content': 'All items in the above table drop together at once.', 'name': 'p20'}]	1	4/150