October birthstone
October's birthstone is opal tourmaline .
Opal is known for its play-of-color effect, which shows an aurora-like glow of seven colors on its surface, but some types do not show this play-of-color effect. Not only are there many types, but each one has a different play of color, so I think it's perfect for those who like unique gemstones.
Tourmaline is a gemstone with so many color variations that it is said that there is no other color. Some are called by different names depending on their color, such as Paraiba tourmaline and rubellite . Some stones have multiple colors in one stone, and others look like watermelons, so I think it's fun to collect a variety of stones and enjoy the different colors.
Karatz GemMagazine
" List of October birthstones and birthstones "
![[On Sale August 2nd at 10 PM JST] Limited to 12 Stones: Blue Gemstone Gacha (Paraiba Tourmaline, Euclase, Tanzanite, etc.) + 1 Aquamarine Stone Included (Bulk Purchase Discount Available)](http://store.karatz.jp/cdn/shop/files/77_ede25372-0894-4b5d-ac9c-3b1ca2b56c4f.png?v=1785146266&width=4000)
![[On sale August 15th at 10 PM] Paraiba Gacha where you can win a Brazilian Paraiba Tourmaline (CuO: 1.4%, MnO: 2.7%) normally priced at 39,800 yen, limited to 10 stones. (Multiple purchase discount available)](http://store.karatz.jp/cdn/shop/files/collage_a0ff6ff6-cfc6-4b64-bdac-9956db0ceb16.png?v=1786092530&width=2000)
![[On Sale July 31st at 10 PM] "Limited to 20 Stones" Indigo Tourmaline Gacha with 5 Gem-Quality Stones + 1 Loose Stone (Certificate Included) (Multiple Purchase Discount Available)](http://store.karatz.jp/cdn/shop/files/80.png?v=1785152112&width=4000)
【8/22 22時販売】ブラジル産ピンクトルマリン 4.9mm/0.400ctルース 宝貴協
Sale price¥15,800
[22602666 listed] [Colorful] K18WG Paraiba Tourmaline 0.09ct Ring
Sale price¥198,000
Brazilian bicolor tourmaline 7.489ct loose
Sale price¥39,800
[Posted as 12563996] Australian Black Opal 1.029ct Loose Stone
Sale price¥29,800
Brazilian Paraiba Tourmaline 0.068ct loose stone
Sale price¥61,800
![【#202607 Akihabara Pop-up Store - Currently Removed for Display】[Colorfuri] Pt900 Black Opal 0.83ct / Diamond 0.62ct Ring with Certificate](http://store.karatz.jp/cdn/shop/files/P4085602_239fb724-e8c8-4f49-8fab-65e692522cdb.jpg?v=1785992300&width=4000)
[Star in cut] Mexican fire opal 7mm/0.678ct loose patch
Sale price¥39,800
[Listed on 12564095] Nigerian Indicolite Tourmaline 0.241ct Loose Stone
Sale price¥25,800
[Listed on 12563931] Australian Opal 0.674ct Loose Gemstone
Sale price¥8,800
[Listed as 12564063] Brazilian Pink Tourmaline 0.689ct Loose Stone
Sale price¥15,800
[Published 12563933] Brazilian Rubellite 1.100ct Loose Stone
Sale price¥98,000
[Listed as 12563246] Mexican Fire Opal 1.115ct Loose
Sale price¥25,800
![[On sale June 28th at 10 PM] Brazilian Paraiba Tourmaline Gacha with sorting results (CuO: 2.1%, MnO: 2.2%), usually ¥45,800, now with a chance to win one of 18 limited stones. (Multiple purchase discount available)](http://store.karatz.jp/cdn/shop/files/collage_6bc80329-36ed-4bc7-bbff-5c77e00a25bd.png?v=1782393589&width=3000)
![Limited to 20 stones: Brazilian Paraiba tourmaline (cabochon cut, approximately 2.2 mm) [Multiple purchase discounts available]](http://store.karatz.jp/cdn/shop/files/PC190060_c4f87b12-3b41-4e2d-a32f-2338f4edfd21.jpg?v=1766651520&width=4000)
![[On Sale June 27, 10 PM JST] "Limited to 10 Stones" Rough Stone Gacha including Paraiba Tourmaline (CuO: 1.7%+ content) and Benitoite (with a bonus Oregon Sunstone) "Multiple Purchase Discount Available"](http://store.karatz.jp/cdn/shop/files/52_a5256d7b-e60a-4b76-822d-f33111c60340.png?v=1782353139&width=2268)
1 stone of green opal from South Africa (discount available for multiple purchases)
Sale priceFrom ¥2,980
![[Option] Paraiba Tourmaline component analysis sorting issuance fee](http://store.karatz.jp/cdn/shop/products/P6062508_58dd99d0-190a-4656-98c6-53c5ff54428e.jpg?v=1680959036&width=4000)
[Option] Paraiba Tourmaline component analysis sorting issuance fee
Sale price¥5,000
![[Sale starts July 20, 10 PM JST] Limited to 9 Stones: Opal Gacha, including Black Opal (plus a free Fire Opal!) (Multiple purchase discount available)](http://store.karatz.jp/cdn/shop/files/2026-07-207.47.29.png?v=1784501274&width=1270)
![[On sale May 4th at 10 PM] "Limited to 11 Gems" Rouge Cut & Heart Shape Gemstone Gacha for ¥18,800! 💎 Almandine Garnet, Pink Tourmaline, Scolecite, Sapphire. "Multiple Purchase Discount Available"](http://store.karatz.jp/cdn/shop/files/22_c08b10af-9494-4ce9-8e59-7047cbe3cc33.png?v=1777603740&width=4000)
![[On Sale May 2, 10 PM JST] 7 Limited Pieces - Mexican Opal, Max. 11ct (Includes items with minor flaws) - Multiple Purchase Discount Available](http://store.karatz.jp/cdn/shop/files/P1010481_db517dff-caf5-40cf-b8d1-e5c10273ddf0.jpg?v=1771719722&width=4000)
Why not take your favorite gemstone that you found at KARATZ and have it made into custom-made jewelry? It will be made by skilled Japanese craftsmen.
We carefully craft each piece of jewelry, starting with the stone setting, to match the individual characteristics of the gemstone.
So that more people can feel closer to jewellery and enjoy it easily.
We will introduce KARATZ's thoughts on products, the attention to detail and efforts in selecting gemstones and creating jewelry.
KARATZ's Initiatives and Social Contributions
We will introduce KARATZ's efforts, including nurturing the next generation and business collaboration to develop the industry, and supporting children in Sri Lanka, the land of jewels.
KARATZ Books
These are books that KARATZ has been involved in writing, supervising, and planning. They are all books that allow you to enjoy gemstones from various angles. You can also purchase them directly.
jeweler's tools
For those who want to enjoy jewelry more but don't know what tools to use, we will introduce tools that are also used by KARATZ staff. You can also purchase them directly.